Merge branch '32-overlay-implementation' into 'master'

Resolve "overlay implementation" Closes #32 See merge request Pmodules/src!2
2026-07-08 14:50:49 +02:00 · 2022-10-27 13:09:40 +00:00
parent e998bfa09b 34a3009120
commit 07d22cf1f2
39 changed files with 4146 additions and 6071 deletions
@@ -11,4 +11,5 @@ Downloads
 tmp
 tclIndex
 pbuild.log
+libpmodules.bash
 *~
@@ -1,5 +1,147 @@
 # Changelog of Pmodules

+## Version 1.1.10 (not yet tagged)
+* **modulecmd**
+  * *User visible changes*
+    * New options for `module search`.
+	  * With the option `--group` the search can be restricted to a
+	    group.
+	  * With the option `--newest` only the newest versions are
+        displayed.
+	* `find` as alias for the sub-command `search` added.
+	* Bugfix: the sub-commands `whatis` and `keyword|apropos` were
+        broken by design. 
+    * Bugfix: after loading a `Pmodules` module, it was not shown with
+      `module list`.
+	* Bugfix in scanning the depth of groups.
+	* Bugfix: after `module purge` the environment variable
+      `PMODULES_HOME` was not defined an more.
+    * Bugfix: source the shell init file only if a `Pmodules` module
+      is loaded.
+	* Bugfix: unsetting aliases in modulefiles was not handled
+      properly in `module purge`
+  * *Internal changes and fixes*
+    * initialisation error for bash and zsh fixed
+
+* **build-system**
+  * *User visible changes*
+    * `modbuild` is now defined as function like `module`. Therefor no
+	`Pmodules` module must be loaded to build a module with `modbuild`
+	* The system can now be defined in the module (YAML) configuration
+      file.
+	* Build dependencies can (and should) now be specified with
+      `build_requires` in the YAML configuration file.
+	* Bugfix: cleanup of modulefiles in overlays fixed. A module can be in
+      more than one overlay. These overlays must be specified in the
+      module configuration file. 
+	* Bugfix: querying dependencies from YAML configuration file
+      fixed. Under some conditions the string 'null' was in the list
+      of dependencies.
+	* Bugfix: create group directory if it doesn't exist.
+	* Bugfix: create the module `$PREFIX` before processing the
+      install targets not before all targets. If `$PREFIX` is created
+      before processing any target and the build fails, `modbuild`
+      assumes that the module have been already built successfully.
+ * *Internal changes and fixes*
+    * code review/re-factoring
+	* `modbuild` is now using the Bash installed in `Pmodules` itself.
+	* test code with `set -o nounset`, several issues with this
+      setting fixed (not necessarily bugs).
+
+* **other changes**
+ * The build script to bootstrap Pmodules itself doesn't use modbuild
+   any more to compile required software packages.  With this change
+   we can remove some special cases from modbuild.
+ * The bootstrap script requires Bash 5.0 or newer now.
+ * Bugfix: in the `Pmodules` modulefile force the sourcing of the
+   shell init script while in mode `load` only.
+
+## Version 1.1.9
+* **modulecmd**
+  * *User visible changes*
+    * Overlay info added to output of sub-command `search`.
+    * Output of `module search --verbose` revised for better readability.
+  * *Internal changes and fixes*
+    * The shell`s init file is sourced, when Pmodules is loaded as module.
+      This is required if there are changes in the module function or too
+      define new shell functions.
+    * A bug in `libmodules.tcl:module-addgroup()` which crashed 
+      `module load ...` has been fixed.
+    * In versions before 1.1.9 a colon at the beginning or end of `MODULEPATH`
+      crashed the module function. This has been fixed. 
+
+* **build-system**
+  * *User visible changes*
+    * The command `modbuild` is now defined as shell function analog to
+      the `module` command. The main reason to introduce this function
+      is due to the fact that Bash version 5 or newer is now required
+      by `modbuild`. The function `modbuild` load Bash 5.x as module
+      before calling the modbuild-script. If you want to use the script
+      directly, a Bash binary with version 5.x must be in PATH.
+    * If a build-script is in the current working directory,
+      `modbuild` can now be called without specifying the build-script.
+    * In case of an error in a build-step the build process did not 
+      abort as it should. This has been fixed.
+    * The option `--overlay` can now be used
+	  - to define an overlay if legacy variants files are used
+	  - to override the overlay in a YAML variants file.
+    * The new keyword `with` has been introduced in YAML variants file
+      to specified hierarchical dependencies.
+    * The function `pbuild::supported_os` has been
+      removed. `pbuild::supported_systems` provides the same
+      functionality for legacy configuration files. In YAML module
+      configuration files `systems` have to be used.
+
+* **Internal changes and fixes**
+    * bugfix in setting `PATH`
+    * requires bash 5 or later
+
+## Version 1.1.8
+* **modulecmd**
+  * *User visible changes*
+    * configuration in YAML files
+    * modulefiles and software must not
+      have a common root directory
+    * the installation root must be specified, it doesn`t default
+      to the base 'overlay' any more.
+    * zsh initialisation fixed.
+  * *Internal changes and fixes*
+    * std::upvar() replaced with reference variables in part of the 
+      code.
+    * environment variable `PMODULES_ROOT` removed.
+    * unsetting aliases fixed.
+    * update to bash 5.1.16
+    * update to findutils 4.9 (macOS only)
+    * minor fixes
+* **build-system**
+  * *User visible changes*
+    * YAML format for variants files
+  * *Internal changes and fixes*
+    * use lib `libpmodules.bash`
+    * bugfixes
+* **modmanage**
+  * *User visible changes*
+    * none, support for overlays still missing
+  * *Internal changes and fixes*
+    * none
+
+## Version 1.1.7
+* **modulecmd**
+  * list of available overlays in subcommand `use` is now better readable
+* **buid-system**
+  * overlay definition must now be in YAML format
+  * support for YAML formatted variant files (the legacy format 
+    is still supported)
+  * build-system in 1.1.6 was still work in progress and broken
+
+## Version 1.1.6
+* **modulecmd**
+  * bugfix in searching/loading modules in a hierarchical
+    group
+
+## Version 1.1.5
+* first public version with the overlay feature
+
 ## Version 1.0.0rc11
 * **modulecmd**
  * *User visible changes*
@@ -11,10 +11,6 @@ fi
 ############################################################################
 # some sanity checks
 #
-if [[ ! -d ${PMODULES_ROOT} ]]; then
-        echo "Oops: ${PMODULES_ROOT}: Set as Pmodules root, but this is not a directory." 1>&2
-        return 1
-fi
 if [[ ! -d ${PMODULES_HOME} ]]; then
        echo "Oops: ${PMODULES_HOME}: Set as Pmodules home, but this is not a directory." 1>&2
        return 1
@@ -33,13 +29,9 @@ fi
 unset MODULE_VERSION
 unset MODULE_VERSION_STACK
 unset MODULESHOME
-unset PMODULES_ENV

-declare -x PMODULES_MODULEFILES_DIR='modulefiles'
-declare -x PMODULES_CONFIG_DIR='config'
 declare -x PMODULES_DIR="${PMODULES_HOME}"

-
 #############################################################################
 # implement module comand as shell function
 #
@@ -49,6 +41,11 @@ module() {
 }
 export -f module

+modbuild(){
+	"${PMODULES_HOME}/bin/modbuild" "$@"
+}
+export -f modbuild
+
 # Local Variables:
 # mode: sh
 # sh-basic-offset: 8
@@ -4,6 +4,7 @@
 # unload modules if parent removed
 #

+
 if {[info exists env(PMODULES_DEBUG)] && $env(PMODULES_DEBUG)} {
 	proc debug {msg} {
 		set level [expr [info level] -2] 
@@ -24,13 +25,35 @@ debug "loading libmodules"

 package require base64

+set ::MODULEFILES_DIR "modulefiles"
+set ::ol_replacing "r"
+
 proc _pmodules_parse_pmodules_env { } {
-        debug "enter"
+	#
+	# In this library we need the value of some BASH variables
+	# defined in PMODULES_ENV. In this function we translate
+	# these variables definitions - created in BASH with
+	# 'typeset -p VAR' - to Tcl.
+	#
 	foreach line [split [base64::decode $::env(PMODULES_ENV)] "\n"] {
 		if { ![regexp -- {.* -[aAx]* (.*)=\((.*)\)} $line -> name value] } {
 			continue
 		}
 		switch $name {
+			Dir2OverlayMap {
+				array set ::Dir2OverlayMap [regsub -all  {[]=[]} $value " "]
+			}
+			OverlayInfo {
+				array set ::OverlayInfo [regsub -all  {[]=[]} $value " "]
+			}
+		        UsedOverlays {
+			        array set tmp [regsub -all  {[]=[]} $value " "]
+  			        set ::UsedOverlays {}
+				set l [lsort [array names tmp]]
+			        foreach k $l {
+				        lappend ::UsedOverlays $tmp($k)
+			        }
+			}
 			UsedGroups {
 				set ::UsedGroups $value
 			}
@@ -55,14 +78,32 @@ proc module-addgroup { group } {
 	set	::${group}_version	$version

 	if { [module-info mode load] } {
-		prepend-path MODULEPATH [file join \
-                                             $::PmodulesRoot \
-                                             $group \
-                                             $::PmodulesModulfilesDir \
-                                             {*}$::variant]
+	        set overlays_to_add {}
+		foreach overlay $::UsedOverlays {
+			lappend overlays_to_add $overlay
+		        set ol_type $::OverlayInfo($overlay:type)
+		        debug "ol_type=$ol_type"
+			if { [string compare $ol_type $::ol_replacing] == 0 } {
+				break
+			}
+		}
+		foreach overlay [lreverse_n $overlays_to_add 1] {
+			debug "overlay=$overlay"
+			debug "group=$group"
+			debug "::variant=$::variant"
+			set dir [file join \
+				     $::OverlayInfo($overlay:mod_root) \
+				     $group \
+				     $::MODULEFILES_DIR \
+				     {*}$::variant]
+		        debug "dir=$dir"
+			if { [file isdirectory $dir] } {
+				debug "prepend $dir to MODULEPATH "
+				prepend-path MODULEPATH $dir
+			}
+		}
+		debug "end foreach"
 		prepend-path UsedGroups $group
-		debug "mode=load: new MODULEPATH=$env(MODULEPATH)"
-		debug "mode=load: new UsedGroups=$env(UsedGroups)"
 	} elseif { [module-info mode remove] } {
 		set GROUP [string toupper $group]
 		debug "mode=remove: hierarchical group '${GROUP}'"
@@ -83,14 +124,15 @@ proc module-addgroup { group } {
 			debug "mode=remove: no orphan modules to unload"
 		}
 		debug "mode=remove: $env(MODULEPATH)"
-                set dir [file join \
-                             $::PmodulesRoot \
-                             $group \
-                             $::PmodulesModulfilesDir \
-                             {*}$::variant]
-                debug "mode=remove: dir=$dir"
-                remove-path MODULEPATH $dir
-		debug "mode=remove: $env(UsedGroups)"
+                foreach overlay $::UsedOverlays {
+                        set dir [file join \
+                                     $overlay \
+                                     $group \
+                                     $::MODULEFILES_DIR \
+                                     {*}$::variant]
+		        debug "remove $dir"
+                        remove-path MODULEPATH $dir
+                }
 		remove-path UsedGroups $group
                debug "mode=remove: $env(UsedGroups)"
 	}
@@ -131,7 +173,7 @@ proc _pmodules_setenv { PREFIX name version } {
 		return
 	}

-	set		NAME			[string toupper $name]
+	set NAME [string toupper $name]
 	regsub -- "-" ${NAME} "_" NAME

 	if { ! [info exist ::dont-setenv] } {
@@ -154,6 +196,9 @@ proc _pmodules_setenv { PREFIX name version } {
 		if { [lsearch ${::dont-setenv} "${NAME}_HOME"] == -1 } {
 			setenv		${NAME}_HOME		$PREFIX
 		}
+		if { [lsearch ${::dont-setenv} "${NAME}_ROOT"] == -1 } {
+			setenv		${NAME}_ROOT		$PREFIX
+		}
 	} else {
 		debug "$PREFIX is not a directory"
 	}
@@ -274,13 +319,45 @@ proc ModulesHelp { } {
 # intialize global vars
 # Modulefile is something like
 #
-#   ${PMODULES_ROOT}/group/${PMODULES_MODULEFILES_DIR}/name/version
+#   <root_dir>/group/modulefiles/name/version
 # or
-#   ${PMODULES_ROOT}/group/${PMODULES_MODULEFILES_DIR}/X1/Y1/name/version
+#   <root_dir>/group/modulefiles/X1/Y1/name/version
 # or
-#   ${PMODULES_ROOT}/group/${PMODULES_MODULEFILES_DIR}/X1/Y1//X2/Y2/name/version
+#   <root_dir>/group/modulefiles/X1/Y1//X2/Y2/name/version
 #
+proc _find_overlay { modulefile_components } {
+        debug "_find_overlay()"
+        foreach ol $::UsedOverlays  {
+                debug "$ol"
+		set ol_mod_root $::OverlayInfo(${ol}:mod_root)
+                if { [string range $ol_mod_root end end] == "/" } {
+                        set ol_mod_root [string range $ol_mod_root 0 end-1]
+                }
+		debug "$ol_mod_root"
+                set ol_mod_root_splitted [file split $ol_mod_root]
+                set modulefile_root [file join \
+					 {*}[lrange \
+						 $modulefile_components \
+						 0 [expr [llength $ol_mod_root_splitted] - 1]]]
+		debug "$modulefile_root"
+                if { [string compare $ol_mod_root $modulefile_root] == 0 } {
+			debug "$ol_mod_root_splitted"
+                        return $ol_mod_root_splitted
+                }
+        }
+        debug "not found"
+        return {}
+}
+
+proc _is_in_overlay { } {
+	debug "_is_in_overlay?"
+	set parts [_find_overlay [file split $::ModulesCurrentModulefile]]
+	debug "_is_in_overlay: $parts"
+	expr {[string compare $parts ""] == 0 }
+}
+
 proc _pmodules_init_global_vars { } {
+	debug "_pmodules_init_global_vars() called"
 	global	group
 	global  GROUP
 	global  name
@@ -292,38 +369,31 @@ proc _pmodules_init_global_vars { } {
 	global	V_PATCHLVL
 	global	V_RELEASE
 	global	V_PKG
-
 	global	variant
 	global	PREFIX		# prefix of package

-	debug	"$::ModulesCurrentModulefile"
-	set	::PmodulesRoot		$::env(PMODULES_ROOT)
-	set	::PmodulesModulfilesDir	$::env(PMODULES_MODULEFILES_DIR)
-	set	modulefile		[file split $::ModulesCurrentModulefile]
-	set	pmodules_root		[file split $::PmodulesRoot]
-	set	pmodules_root_num_dirs	[llength $pmodules_root]
+	set	modulefile_splitted	[file split $::ModulesCurrentModulefile]

-	set	modulefile_root	[file join {*}[lrange $modulefile 0 \
-                                                   [expr $pmodules_root_num_dirs - 1]]]
-	if { $::PmodulesRoot != $modulefile_root } {
-		debug "stop sourcing: ${::PmodulesRoot} != $modulefile_root"
-		return
-	} 
-	debug	"modulefile is inside our root"
-	set	rel_modulefile	[lrange $modulefile [llength $pmodules_root] end]
+	set     ol_mod_root_splitted [_find_overlay ${modulefile_splitted}]
+	set	rel_modulefile	[lrange $modulefile_splitted [llength $ol_mod_root_splitted] end]
 	set	group		[lindex $rel_modulefile 0]
 	set	GROUP		"${group}"
-	set	name		[lindex $modulefile end-1]
+	set	name		[lindex $modulefile_splitted end-1]
 	set	P		"${name}"
-	set	version		[lindex $modulefile end]
+	set	version		[lindex $modulefile_splitted end]
 	set 	V		"${version}"
 	lassign [split $V -]	V_PKG tmp
 	set	V_RELEASE	[lindex [split $tmp _] 0]
 	lassign [split $V_PKG .] V_MAJOR V_MINOR V_PATCHLVL
-	set	variant	[lrange $rel_modulefile 2 end]
-	set	prefix		"$pmodules_root $group [lreverse_n $variant 2]"
+	set	variant 	[lrange $rel_modulefile 2 end]
+	set mod_root [file join {*}$ol_mod_root_splitted]
+	debug "mod_root=$mod_root"
+	set ol $::Dir2OverlayMap($mod_root)
+	debug "ol=$ol"
+	set install_prefix [file split $::OverlayInfo(${ol}:inst_root)]
+	set	prefix		"$install_prefix $group [lreverse_n $variant 2]"
 	set	PREFIX		[file join {*}$prefix]
-
+	debug "PREFIX=$PREFIX"
 	debug "group of module $name: $group"
 }

@@ -331,14 +401,13 @@ if { [info exists ::whatis] } {
 	module-whatis	"$whatis"
 }

-_pmodules_init_global_vars 
-
-#
-# we cannot load another module with the same name
-#
-conflict	$name
-
-_pmodules_setenv ${PREFIX} ${name} ${version}
-_pmodules_update_loaded_modules ${group} ${name} ${version}
-
+_pmodules_parse_pmodules_env
+if {[_is_in_overlay] == 0} {
+	debug "setup env vars for module in overlay"
+	_pmodules_init_global_vars 
+	conflict	$name
+    	_pmodules_setenv ${PREFIX} ${name} ${version}
+	_pmodules_update_loaded_modules ${group} ${name} ${version}
+}
 debug "return from lib"
+
@@ -1,24 +0,0 @@
-#!/bin/bash
-
-eval "pbuild::pre_prep_${system}() { :; }"
-eval "pbuild::pre_prep_${OS}() { :; }"
-eval "pbuild::post_prep_${system}() { :; }"
-eval "pbuild::post_prep_${OS}() { :; }"
-
-eval "pbuild::add_patch_${system}() { pbuild::add_patch \"\$@\"; }"
-eval "pbuild::add_patch_${OD}() { pbuild::add_patch \"\$@\"; }"
-
-eval "pbuild::pre_configure_${system}() { :; }"
-eval "pbuild::pre_configure_${OS}() { :; }"
-eval "pbuild::post_configure_${system}() { :; }"
-eval "pbuild::post_configure_${OS}() { :; }"
-
-eval "pbuild::pre_compile_${system}() { :; }"
-eval "pbuild::pre_compile_${OS}() { :; }"
-eval "pbuild::post_compile_${system}() { :; }"
-eval "pbuild::post_compile_${OS}() { :; }"
-
-eval "pbuild::pre_install_${system}() { :; }"
-eval "pbuild::pre_install_${OS}() { :; }"
-eval "pbuild::post_install_${system}() { :; }"
-eval "pbuild::post_install_${OS}() { :; }"
@@ -7,9 +7,19 @@ declare -A Subcommands=()
 declare -A Options=()
 declare -A Help=()

+declare -a Overlays=()
+declare -A OverlayInfo
+declare -a UsedOverlays
+declare -A Dir2OverlayMap
+
+declare -r ol_normal='n'
+declare -r ol_hiding='h'
+declare -r ol_replacing='r'
+
+
 # initialize help text of 'module --version'
 Help['version']="
-Pmodules @PMODULES_VERSION@ using Tcl Environment Modules @MODULES_VERSION@
+Pmodules @PMODULES_VERSION@ using Tcl Environment Modules 
 Copyright GNU GPL v2
 "

@@ -28,34 +38,147 @@ print_help() {
 #       $1: absolute path of a modulefile directory
 #
 compute_group_depth () {
-        local -r dir=$1
-	test -d "${dir}" || return 1
+	local -n result="$1"
+        local -r dir="$2"
+	if [[ ! -d "${dir}" ]]; then
+		${mkdir} -p "${dir}" || \
+			std::die 1 "Cannot create directory -- ${dir}"
+	fi
        local group=${dir%/*}
        local group=${group##*/}
-        [[ -n "${GroupDepths[${group}]}" ]] && return 0
-	local -i depth=$(${find} "${dir}" -depth \( -type f -o -type l \) \
+	result=$(${find} "${dir}" -depth \( -type f -o -type l \) \
                          -printf "%d" -quit 2>/dev/null)
-	(( depth-=2 ))
+	(( result-=2 ))
 	# if a group doesn't contain a modulefile, depth is negativ
 	# :FIXME: better solution?
-	(( depth < 0 )) && (( depth = 0 ))
-	GroupDepths[$group]=${depth}
+	(( result < 0 )) && (( result = 0 ))
 }

 #
-# (Re-)Scan available groups in given root and compute group depth's
+# (Re-)Scan available groups in given overlays and compute group depth's
 #
 # Args:
-#       $1: root of modulefile hierarchy
+#       $@: overlay names
 #
 scan_groups () {
-	local -r root="$1"
-	local moduledir
-	for moduledir in ${root}/*/${PMODULES_MODULEFILES_DIR}; do
-		compute_group_depth "${moduledir}"
+        local    ol
+	local depth
+        for ol in "$@"; do
+		local mod_root="${OverlayInfo[${ol}:mod_root]}"
+	        local dir
+	        for dir in ${mod_root}/*/${PMODULES_MODULEFILES_DIR}; do
+			local group="${dir%/*}"
+			group="${group##*/}"
+			if [[ ! -v GroupDepths[${group}] ]]; then
+				compute_group_depth depth "${dir}"
+				GroupDepths[$group]=${depth}
+			fi
+			Dir2OverlayMap[${dir%/${PMODULES_MODULEFILES_DIR}*}]="${ol}"
+	        done
+        done
+}
+
+pm::read_config(){
+	local -a config_files=()
+	
+	_get_config_files(){
+		#
+		# return array with overlay configuration files
+		#
+		# Args:
+		#	$1	[upvar] result
+		local -n fnames="$1"
+
+		# user defined via environment variable
+		if [[ -v PMODULES_OVERLAYS_DEF ]]; then
+			test -r "${PMODULES_OVERLAYS_DEF}" || \
+				std::die 3 \
+					 "%s -- %s" \
+					 "overlay definition file is not readable" \
+					 "$_"
+			fnames+=("${PMODULES_OVERLAYS_DEF}")
+		fi
+
+		# user defined
+		if [[ -r "${HOME}/.Pmodules/Pmodules.yaml" ]]; then
+			fnames+=("${HOME}/.Pmodules/Pmodules.yaml")
+		fi
+
+		# system config file
+		test -r "${PMODULES_HOME%%/Tools*}/config/Pmodules.yaml" || \
+			std::die 3 \
+				 "%s %s -- %s" \
+				 "base overlay definition file" \
+				 "does not exist or is not readable" \
+				 "$_"
+		
+		fnames+=("${PMODULES_HOME%%/Tools*}/config/Pmodules.yaml")
+	}
+
+	_get_ol_names(){
+		#
+		# get the names of all overlays
+		#
+		local -n fnames="$1"
+		${yq} -Ne eval-all '. as $item ireduce ({}; . *+ $item) |.Overlays|keys()' \
+		      "${fnames[@]}" | awk '{print $2}'
+	}
+
+	_get_config_files config_files
+
+	eval $(std::parse_yaml "${config_files[-1]}" 'cfg_')
+	[[ -v cfg_DefaultGroups ]] && DefaultGroups="${cfg_DefaultGroups}"
+	[[ -v cfg_DefaultReleaseStages ]] && DefaultReleaseStages="${cfg_DefaultReleaseStages}"
+	[[ -v cfg_ReleaseStages ]] && ReleaseStages="${cfg_ReleaseStages}"
+	unset ${!cfg_*}
+
+	#
+	# loop over all overlays and save config in OverlayInfo and Dir2OverlayMap
+	#
+	# - at least install_root must be specified
+	# - modulefiles_root default so install_root
+	# - the type defaults to ${ol_normal}
+	#
+	Overlays=( $(_get_ol_names config_files) )
+	local ol=''
+	for ol in "${Overlays[@]}"; do
+		eval $(${yq} -Ne eval-all \
+			  ". as \$item ireduce ({}; . *+ \$item) |.Overlays.${ol}" \
+			  "${config_files[@]}" | \
+			       sed 's/: /=/; s/\(.*\)/local \1/')
+
+		[[ -n ${install_root} ]] || \
+			std::die 3 \
+				 "install_root missing for overlay -- ${ol}"
+		[[ -d ${install_root} ]] || \
+			std::die 3 \
+				 "Invalid installation root directory for overlay '${ol}' -- ${install_root}"
+		OverlayInfo[${ol}:inst_root]="${install_root}"
+
+		: ${modulefiles_root:=${install_root}}
+		[[ -d ${modulefiles_root} ]] || \
+			std::die 3 \
+				 "Invalid modulefiles root directory for overlay '${ol}' -- ${modulefiles_root}"
+		OverlayInfo[${ol}:mod_root]="${modulefiles_root}"
+		Dir2OverlayMap[${modulefiles_root}]="${ol}"
+		
+		: ${type:=${ol_normal}}
+		case ${type} in
+			${ol_normal} | ${ol_replacing} | ${ol_hiding} )
+				:
+				;;
+			* )
+				std::die 3 "Invalid type for overlay '${ol}' -- ${type}"
+				;;
+		esac
+		OverlayInfo[${ol}:type]="${type}"
+
+		OverlayInfo[${ol}:used]='no'
+		unset type modulefiles_root install_root
 	done
 }

+
 # Local Variables:
 # mode: sh
 # sh-basic-offset: 8
@@ -20,7 +20,7 @@ std::error() {
 }

 std::debug() {
-        [[ ${PMODULES_DEBUG} ]] || return 0
+        [[ -v PMODULES_DEBUG ]] || return 0
        std::log 2 "$@"
 }

@@ -39,7 +39,7 @@ std::def_cmds(){
 	local path="$1"
 	shift
 	for cmd in "$@"; do
-		eval declare -g ${cmd}=$(PATH="${path}" which $cmd 2>/dev/null)
+		eval declare -gr ${cmd}=$(PATH="${path}" /usr/bin/which $cmd 2>/dev/null)
 		if [[ -z "${!cmd}" ]]; then
 			std::die 255 "${cmd} not found"
 		fi
@@ -78,42 +78,54 @@ std::get_abspath() {
 }

 std::append_path () {
-	local -r P=$1
-	local -r d=$2
+        local -nr P="$1"
+	shift 1
+	local dir
+	local dirs=''
+	for dir in "$@"; do
+		[[ "${P}" == @(|*:)${dir}@(|:*) ]] && continue
+		dirs+=":${dir}"
+	done

-        if ! echo ${!P} | egrep -q "(^|:)${d}($|:)" ; then
-		if [[ -z ${!P} ]]; then
-			export "$P=${d}"
-		else
-			export "$P=${!P}:${d}"
-        	fi
-	fi
+        if [[ -z ${P} ]]; then
+                P="${dirs:1}"		# remove leading ':'
+        else
+		P="${P}${dirs}"
+        fi
 }

 std::prepend_path () {
-        local -r P=$1
-        local -r d=$2
+        local -nr P="$1"
+	shift 1

-        if ! echo ${!P} | egrep -q "(^|:)${d}($|:)" ; then
-                if [[ -z ${!P} ]]; then
-                        export "$P=${d}"
-                else
-                        export "$P=${d}:${!P}"
-                fi
+	local dir
+	local dirs=''
+	for dir in "$@"; do
+		[[ "${P}" == @(|*:)${dir}@(|:*) ]] && continue
+		dirs+="${dir}:"
+	done
+
+        if [[ -z ${P} ]]; then
+                P="${dirs:0:-1}"	# remove trailing ':'
+        else
+		P="${dirs}${P}"
        fi
 }

 std::remove_path() {
-        local -r P=$1
-        local -r d=$2
+        local -nr P="$1"
+	shift 1
+        local -ar dirs="$@"
 	local new_path=''
 	local -r _P=( ${!P//:/ } )
-	# loop over all entries in path
-	for entry in "${_P[@]}"; do
-		[[ "${entry}" != "${d}" ]] && new_path+=":${entry}"
+	local dir=''
+	for dir in "${dirs[@]}"; do
+		# loop over all entries in path
+		for entry in "${_P[@]}"; do
+			[[ "${entry}" != "${dir}" ]] && new_path+=":${entry}"
+		done
 	done
-	# remove leading ':'
-	eval ${P}="${new_path:1}"
+	P="${new_path:1}"		# remove leading ':'
 }

 #
@@ -163,22 +175,23 @@ std::replace_path () {
 #     analog to std::split_abspath() with a relative path.
 #
 std::split_path() {
-	local parts="$1"
-	local  -r path="$2"
+	local -n parts="$1"
+	local -r path="$2"

        IFS='/'
        local std__split_path_result=( ${std__split_path_tmp} )
 	unset IFS
-	std::upvar ${parts} "${std__split_path_result[@]}"
+	parts="${std__split_path_result[@]}"
 	if (( $# >= 3 )); then
 		# return number of parts
-	        std::upvar "$3" ${#std__split_path_result[@]}
+		local -n num="$3"
+	        num="${#std__split_path_result[@]}"
 	fi
 }

 std::split_abspath() {
-	local parts="$1"
-	local  -r path="$2"
+	local -n parts="$1"
+	local -r path="$2"
 	if [[ "${path:0:1}" == '/' ]]; then
 		local -r std__split_path_tmp="${path:1}"
 	else
@@ -188,16 +201,17 @@ std::split_abspath() {
        IFS='/'
        local std__split_path_result=( ${std__split_path_tmp} )
 	unset IFS
-	std::upvar ${parts} "${std__split_path_result[@]}"
+	parts="${std__split_path_result[@]}"
 	if (( $# >= 3 )); then
 		# return number of parts
-	        std::upvar "$3" ${#std__split_path_result[@]}
+		local -n num="$3"
+	        num="${#std__split_path_result[@]}"
 	fi
 }

 std::split_relpath() {
-	local parts="$1"
-	local  -r path="$2"
+	local -n parts="$1"
+	local -r path="$2"
 	if [[ "${path:0:1}" == '/' ]]; then
 		std::die 255 "Oops: Internal error in '${FUNCNAME[0]}' called by '${FUNCNAME[1]}' }"
 	else
@@ -207,10 +221,11 @@ std::split_relpath() {
        IFS='/'
        local std__split_path_result=( ${std__split_path_tmp} )
 	unset IFS
-	std::upvar ${parts} "${std__split_path_result[@]}"
+	parts="${std__split_path_result[@]}"
 	if (( $# >= 3 )); then
 		# return number of parts
-	        std::upvar "$3" ${#std__split_path_result[@]}
+		local -n num="$3"
+	        num="${#std__split_path_result[@]}"
 	fi
 }

@@ -274,11 +289,11 @@ std::upvar() {
 }

 std.get_os_release_linux() {
-        local lsb_release=$(which lsb_release)
+        #local lsb_release=$(which lsb_release)
        local ID=''
        local VERSION_ID=''

-        if [[ -n $(which lsb_release) ]]; then
+        if [[ -n $(which lsb_release 2>/dev/null) ]]; then
                ID=$(lsb_release -is)
                VERSION_ID=$(lsb_release -rs)
        elif [[ -r '/etc/os-release' ]]; then
@@ -309,7 +324,7 @@ std::get_os_release() {
 	local -A func_map;
 	func_map['Linux']=std.get_os_release_linux
 	func_map['Darwin']=std.get_os_release_macos
-	${func_map[${OS}]}
+	${func_map[$(uname -s)]}
 }

 std::get_type() {
@@ -339,6 +354,29 @@ std::get_type() {
 	esac
 }

+std::parse_yaml() {
+	#
+	# parse a YAML file
+	# See: https://gist.github.com/pkuczynski/8665367
+	#
+	local -r fname="$1"
+	local -r prefix="$2"
+	local s='[[:space:]]*' w='[a-zA-Z0-9_]*' fs=$(echo @|tr @ '\034')
+	sed -ne "s|^\($s\)\($w\)$s:$s\"\(.*\)\"$s\$|\1$fs\2$fs\3|p" \
+            -e "s|^\($s\)\($w\)$s:$s\(.*\)$s\$|\1$fs\2$fs\3|p" "${fname}" |
+		awk -F$fs '{
+		      indent = length($1)/2;	
+		      vname[indent] = $2;	
+		      for (i in vname) {
+                          if (i > indent) {delete vname[i]}
+                      }
+		      if (length($3) > 0) {
+		          vn="";
+                          for (i=0; i<indent; i++) {vn=(vn)(vname[i])("_")}
+		          printf("%s%s%s=\"%s\"\n", "'$prefix'",vn, $2, $3);
+	              }
+                }'
+}
 # Local Variables:
 # mode: sh
 # sh-basic-offset: 8
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!@BASH@
 #
 # The following build specific variables are set and used in libpbuild.bash:
 #       ARGS
@@ -7,38 +7,59 @@
 #
 #.............................................................................

+set -x
 declare VERSION='@PMODULES_VERSION@'

 # get absolute path of script
 declare	    mydir=$(dirname "$0")
 declare -r  mydir=$(cd ${mydir} && pwd -P)

-# initialize PATH,
-# add library installation directories to the PATH,
-# so 'source' is able find them
-
-if [[ $(uname -s) == 'Darwin' ]]; then
-        PATH='/usr/local/bin:'
-else
-        PATH=''
-fi
-PATH+='/usr/bin:/bin:/usr/sbin:/sbin'
-PATH+=":${mydir}"
-PATH+=":${mydir}/../lib:${mydir}/../config"
-
-source libstd.bash    || {
+source "${mydir}/../lib/libstd.bash" || {
        echo "Oops: cannot source library -- '$_'" 1>&2; exit 3;
 }

-# can be set in the configuration file
-declare         PMODULES_DISTFILESDIR=''
-declare         PMODULES_TMPDIR=''
+##############################################################################
+#
+# check availability of used commands and set environment variables
+#   cmd=$(which cmd)
+# in the following we use these environment variable to call binaries.
+#
+declare -r MODULECMD="${PMODULES_HOME}/bin/modulecmd"
+[[ -x ${MODULECMD} ]] || \
+	std::die 1 "Oops: modulecmd binary not available!"

-source libpbuild.bash    || \
+std::def_cmds "${mydir}/../libexec" \
+	      'yq'
+
+std::def_cmds '/usr/bin:/bin:/usr/sbin:/sbin' \
+	      'awk' 'base64' 'cat' 'cp' 'find' 'getopt' 'grep' \
+	      'install' 'logger' 'make' 'mkdir' 'mktemp' 'patch' 'pwd' \
+	      'rm' 'rmdir' 'sort' 'tar' 'tee' 'uname'
+
+declare -r OS="$(${uname} -s)"
+if [[ ${OS} == 'Darwin' ]]; then
+	std::def_cmds '/usr/bin:/bin:/usr/sbin:/sbin:/opt/local/bin' \
+		      'curl' 'otool' 'shasum' 'sysctl'
+	declare -r sha256sum="${shasum -a 256}"
+else
+	std::def_cmds '/usr/bin:/bin:/usr/sbin:/sbin' \
+		      'ldd' 'curl' 'sha256sum'
+fi
+
+# for the time being, we still set PATH. Just in case we forgot a binary
+PATH='/usr/bin:/bin:/usr/sbin:/sbin'
+
+##############################################################################
+source "${mydir}/../lib/libpbuild.bash"    || \
+        std::die 3 "Oops: cannot source library -- '$_'"
+source "${mydir}/../lib/libpmodules.bash"  || \
        std::die 3 "Oops: cannot source library -- '$_'"

-# save arguments, (still) required for building dependencies
-declare -r ARGS="$@"
+##############################################################################
+set   -o	nounset
+shopt -s	nocaseglob
+shopt -s	extglob
+shopt -s	nullglob

 ##############################################################################
 #
@@ -80,7 +101,7 @@ BUILD-STEPS OPTIONS:
 --all
 	Run throu all steps including cleanup.

--update-modulefiles
+-update-modulefiles
 	Only install the modulefile and set the release.

 MISCELLANEOUS OPTIONS:
@@ -94,6 +115,9 @@ MISCELLANEOUS OPTIONS:
 -v | --verbose )
        Verbose output.

+--debug )
+	Run in debug mode.
+
 -j N | --jobs=N
        Run N parallel make jobs.

@@ -119,11 +143,13 @@ MISCELLANEOUS OPTIONS:
 	remove all files created during building.

 --distdir
-	Directory wwhere to store and lookup downloaded files.
+	Directory where to store and lookup downloaded files.

 --tmpdir
        Directory used for building a module.

+--overlay
+        Install in this overlay. Defaults to '${PMODULES_HOME%%/Tools*}'.
 "
 	exit 1
 }
@@ -136,10 +162,13 @@ MISCELLANEOUS OPTIONS:
 # then configuration file
 # last default

+# save arguments, required for building dependencies
+declare -r	ARGS="$@"
+declare         PMODULES_DISTFILESDIR=''
+declare         PMODULES_TMPDIR=''
+
 # versions to be build, '.*' or none means all
 declare -a      versions=()
-declare         opt_bootstrap='no'
-declare 	opt_build_config='modbuild.conf'
 declare         opt_build_target='all'
 declare         opt_dry_run='no'
 declare         opt_enable_cleanup_build='yes'
@@ -148,9 +177,13 @@ declare         opt_force_rebuild='no'
 declare -i      opt_jobs=0
 declare         opt_update_modulefiles='no'
 declare         opt_system=''
+declare		opt_overlay=''
 declare         opt_verbose='no'
 # array collecting all modules specified on the command line via '--with=module'
 declare -a      opt_with_modules=()
+declare --	opt_config_file=''
+
+declare		BUILD_SCRIPT=''

 parse_args() {
 	while (( $# > 0 )); do
@@ -181,13 +214,6 @@ parse_args() {
 		--dry-run )
 			opt_dry_run='yes'
 			;;
-		--config )
-			opt_build_config="$2"
-			shift 1
-			;;
-		--config=* )
-			opt_build_config="${1#*=}"
-			;;
 		--enable-cleanup )
 			opt_enable_cleanup_build='yes'
 			opt_enable_cleanup_src='yes'
@@ -208,51 +234,68 @@ parse_args() {
 		--disable-cleanup-src )
 			opt_enable_cleanup_src='no'
 			;;
-		--distdir )
-			PMODULES_DISTFILESDIR="$2"
-			shift
+		--distdir | --distdir=* )
+			if [[ $1 == *=* ]]; then
+				PMODULES_DISTFILESDIR="${1/--distdir=}"
+			else
+				PMODULES_DISTFILESDIR="$2"
+				shift
+			fi
 			;;
-		--distdir=* )
-			PMODULES_DISTFILESDIR="${1/--distdir=}"
+		--tmpdir | --tmpdir=* )
+			if [[ $1 == *=* ]]; then
+				PMODULES_TMPDIR="${1#--*=}"
+			else
+				PMODULES_TMPDIR="$2"
+				shift
+			fi
 			;;
-		--tmpdir )
-                        PMODULES_TMPDIR="$2"
-			shift
+		--system | --system=* )
+			if [[ $1 == *=* ]]; then
+				opt_system="${1#--*=}"
+			else
+				opt_system="$2"
+				shift
+			fi
 			;;
-		--tmpdir=* )
-			PMODULES_TMPDIR="${1/--tmpdir=}"
+		--overlay | --overlay=* )
+			if [[ $1 == *=* ]]; then
+				opt_overlay="${1#--*=}"
+			else
+				opt_overlay="$2"
+				shift
+			fi
 			;;
-		--system )
-			opt_system="$2"
-			shift
+		--use-flags | --use-flags=* )
+			if [[ $1 == *=* ]]; then
+				USE_FLAGS=":${1#--*=}:"
+			else
+				USE_FLAGS=":$2:"
+				shift
+			fi
 			;;
-		--system=* )
-			opt_system="${1/*=}"
-			;;
-		--use-flags )
-			USE_FLAGS="y:$2:"
-			shift
-			;;
-		--use-flags=* )
-			USE_FLAGS=":${1/--use-flags=}:"
-			;;
-		--with )
-			opt_with_modules+=( "$2" )
-			shift
-			;;
-		--with=*/* )
-			m="${1/--with=}"
-			opt_with_modules+=( ${m} )
+		--with | --with=*/* )
+			if [[ $1 == *=* ]]; then
+				opt_with_modules+=( "${1#--*=}" )
+			else
+				opt_with_modules+=( "$2" )
+				shift
+			fi
 			;;
 		--prep | --configure | --compile | --install | --all )
 			opt_build_target=${1:2}
 			;;
-		--bootstrap )
-			opt_bootstrap='yes'
-			;;
 		--update-modulefiles )
 			opt_update_modulefiles='yes'
 			;;
+		--config-file | --config-file=* )
+			if [[ $1 == *=* ]]; then
+				opt_config_file=( "${1#--*=}" )
+			else
+				opt_config_file=( "$2" )
+				shift
+			fi
+			;;
                -- )
                        :
                        ;;
@@ -280,57 +323,72 @@ parse_args() {
 		esac
 		shift
 	done	
-	[[ -n ${BUILD_SCRIPT} ]] || std::die 1 "No build-block specified!"
+	if [[ -z ${BUILD_SCRIPT} ]]; then
+		if [[ -r "${PWD}/build" ]]; then
+			if grep -q '#!.* modbuild' "${PWD}/build"; then
+				BUILD_SCRIPT="${PWD}/build"
+				BUILDBLOCK_DIR=$(dirname "${BUILD_SCRIPT}")
+			fi
+		fi
+		if [[ -z ${BUILD_SCRIPT} ]]; then
+			std::die 1 "Don't know what to build!"
+		fi
+	fi
 	(( ${#versions[@]} > 0)) || versions+=( '.*' )
 }

-shopt -s nocaseglob
-find_variants_files(){
-        shopt -q nullglob || :
-        local -i nullglob_set=$?
-        shopt -s nullglob
-        local files=( "${BUILDBLOCK_DIR}"/*/"${BNAME_VARIANTS}"\.${opt_system} )
-        files+=( "${BUILDBLOCK_DIR}"/*/"${BNAME_VARIANTS}.$(uname -s)" )
-        local f
-	for f in "${BUILDBLOCK_DIR}"/*/"${BNAME_VARIANTS}"; do
-		[[ -e "${f}.${opt_system}" ]] \
-                        || [[ -e "${f}.$(uname -s)" ]] \
-                        || files+=( "$f" )
-	done
-        (( nullglob_set == 1 )) && shopt -u nullglob
-	std::upvar "$1" "${files[@]}"
+#
+# bash brace expansion of given args. Input args like:
+#
+#   "text" "gcc/{9.3.0,10.3.0}" "openmpi/{4.0.5,4.1.0}"
+#
+# will be expanded to the following four lines:
+#
+#   "text gcc/9.3.0 openmpi/4.0.5"
+#   "text gcc/9.3.0 openmpi/4.1.0"
+#   "text gcc/10.3.0 openmpi/4.0.5"
+#   "text gcc/10.3.0 openmpi/4.1.0"
+#
+bash_expand(){
+	local text="$1"
+	shift
+	local to_expand=( "${@}" )
+	if (( ${#to_expand[@]} == 0 )); then
+		echo ${text}
+	else
+		local list
+		eval list=( ${to_expand[0]} )
+		local s
+		for s in ${list[*]}; do
+			bash_expand "${text} ${s}" "${to_expand[@]:1}"
+		done;
+	fi;
 }

-shopt -s extglob
-expand_variants_file(){
-	expand_deps(){
-		local text="$1"
-                shift
-		local deps=( "${@}" )
-                echo "${deps[@]}"
-                if (( ${#deps[@]} == 0 )); then
-                        echo ${text}
-		else
-                        local list
-		        eval list=( ${deps[0]} )
-			for dep in ${list[*]}; do
-				expand_deps "${text} ${dep}" "${deps[@]:1}"
-			done
-		fi
+build_modules_legacy() {
+	find_variants_files(){
+		local files=( "${BUILDBLOCK_DIR}"/*/"${BNAME_VARIANTS}"\.${opt_system} )
+		files+=( "${BUILDBLOCK_DIR}"/*/"${BNAME_VARIANTS}.$(uname -s)" )
+		local f
+		for f in "${BUILDBLOCK_DIR}"/*/"${BNAME_VARIANTS}"; do
+			[[ -e "${f}.${opt_system}" ]] \
+				|| [[ -e "${f}.$(uname -s)" ]] \
+				|| files+=( "$f" )
+		done
+		std::upvar "$1" "${files[@]}"
 	}

-	local -r input="$1"
-	while read -a toks; do
-		# skip empty and comment lines
-		[[ -z ${toks} ]] && continue
-		[[ ${toke:0:1} == '#' ]] && continue
-                # ignore first (module/version) and second (release) token
-		deps=( ${toks[*]:2} )
-		expand_deps "${toks[0]} ${toks[1]}" "${deps[@]}"
-	done < "${input}"
-}
+	expand_variants_file(){
+		local -r input="$1"
+		while read -a toks; do
+			# skip empty and comment lines
+			[[ -z ${toks} ]] && continue
+			[[ ${toke:0:1} == '#' ]] && continue
+			local -a deps=( ${toks[*]:2} )
+			bash_expand "${toks[0]} ${toks[1]}" "${deps[@]}"
+		done < "${input}"
+	}

-build_modules() {
        local name="$1"
        local version="$2"
        local exact_match='no'
@@ -350,25 +408,17 @@ build_modules() {
        local m
 	local pattern="/^${name}\/${version}[[:blank:]]/"
 	for m in "${with_modules[@]}"; do
-                if [[ -n $(awk "/${m%/*}[\/ ]/" "${files[@]}") ]]; then
+                if [[ -n $(${awk} "/${m%/*}[\/ ]/" "${files[@]}") ]]; then
 		        pattern+=" && /${m//\//\\/}/"
                fi
 	done

-        
        local variants=()
-        local variants_files=()
        for f in "${files[@]}"; do
                local line=''
                while read line; do
                        variants+=( "${line}" )
-                        variants_files+=( "$f" )
-                done < <(expand_variants_file "${f}" | awk "${pattern}")
-                # here we should add a check, whether the version of the
-                # found variants are in the right variants files. Example:
-                # a variant for hdf5/1.10.4 is not allowed in a variants file
-                # for version 1.8. For this we need the mapping of a variant
-                # to the variants file in array 'variants_files'
+                done < <(expand_variants_file "${f}" | ${awk} "${pattern}")
        done
        if (( ${#variants[@]} == 0 )); then
 		std::info "%s " \
@@ -383,6 +433,10 @@ build_modules() {
                done
                std::die 10 "Aborting..."
        fi
+	declare ol_name='base'
+	declare ol_type='n'
+	declare ol_mod_root="${PMODULES_HOME%%/Tools*}"
+	declare ol_inst_root="${PMODULES_HOME%%/Tools*}"
        local -i i=0
        local -i num_variants=${#variants[@]}
        for ((i = 0; i < num_variants; i++)); do
@@ -391,20 +445,224 @@ build_modules() {
                version="${tokens[0]#*/}"
                release="${tokens[1]}"
                with_modules=( "${tokens[@]:2}" )
-                pbuild.build_module \
+                pbuild.build_module_legacy \
                        "${name}" "${version}" \
                        "${release}" "${with_modules[@]}"
        done
 }

+build_modules_yaml(){
+	local -A mod_overlays=()
+	local -- fname="${opt_config_file:-${BUILDBLOCK_DIR}/files/config.yaml}"
+	[[ -r "${fname}" ]] || \
+		std::die 3 "YAML configuration file is not readable -- ${fname}"
+	echo "Using ${fname}..."
+	yaml_get_versions(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		_result=( $(${yq} -Ne e \
+			       "with_entries(select(.key | test(\"^${version}\$\")))|keys" \
+			       "${fname}" 2>/dev/null | ${awk} '{print $2}') )
+	}
+
+	yaml_get_num_variants(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		_result=$(${yq} -Ne e ".\"${version}\"|length" \
+			     "${fname}" 2>/dev/null)
+		if (( $? != 0 )); then
+			_result=0
+		fi
+	}
+
+	yaml_get_relstage(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+		_result=$(${yq} -Ne e ".\"${version}\"[${idx}].relstage" \
+			     "${fname}" 2>/dev/null)
+		(( $? == 0 )) && return
+		_result=$(${yq} -Ne e ".relstage" "${fname}" 2>/dev/null)
+		(( $? == 0 )) && return
+		_result='unstable'
+	}
+	
+	yaml_get_overlay(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+		_result=$(${yq} -Ne e ".\"${version}\"[${idx}].overlay" \
+			     "${fname}" 2>/dev/null)
+		(( $? == 0 )) && return
+		_result=$(${yq} -Ne e ".overlay" "${fname}" 2>/dev/null)
+		(( $? == 0 )) && return
+		_result='base'
+	}
+
+	yaml_get_group(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+		_result=$(${yq} -Ne e ".\"${version}\"[${idx}].group" \
+			     "${fname}" 2>/dev/null)
+		(( $? == 0 )) && return
+		_result=$(${yq} -Ne e ".group" "${fname}" 2>/dev/null)
+		(( $? == 0 )) && return
+		_result=''
+	}
+
+	yaml_get_systems(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+		_result=( $(${yq} -Ne e ".\"${version}\"[${idx}].systems" \
+			     "${fname}" 2>/dev/null) )
+		(( $? == 0 )) && return
+		_result=( $(${yq} -Ne e ".systems" "${fname}" 2>/dev/null) )
+		(( $? == 0 )) && return
+		_result=()
+	}
+
+	yaml_get_compilers(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+		_result=( $(${yq} -Ne e ".\"${version}\"[${idx}].compilers" \
+			     "${fname}" 2>/dev/null) )
+		(( $? == 0 )) && return
+		_result=( $(${yq} -Ne e ".compilers" "${fname}" 2>/dev/null) )
+		(( $? == 0 )) && return
+		_result=()
+	}
+
+	yaml_get_dependencies(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+       		_result=( $(${yq} -Ne e ".\"${version}\"[${idx}]|(.with, .dependencies)" \
+			       "${fname}" 2>/dev/null) )
+		if (( $? != 0 )); then
+			# neither .with nor .dependencies are set
+			_result=()
+			return
+		fi
+		# if one of .with, .dependencies is not set, the vaulue is
+		# returned as 'null'.
+		local -i i
+		for i in "${!_result[@]}"; do
+			[[ ${_result[$i]} == 'null' ]] && unset -v '_result[$i]'
+		done
+		_result=("${_result[@]}")
+	}
+
+	yaml_get_build_requirements(){
+		local -n _result="$1"
+		local fname="$2"
+		local version="$3"
+		local idx="$4"
+       		_result=( $(${yq} -Ne e ".\"${version}\"[${idx}].build_requires" \
+			       "${fname}" 2>/dev/null) )
+		if (( $? != 0 )); then
+			_result=()
+			return
+		fi
+	}
+
+	local name="$1"
+        local version="$2"
+	shift 2
+        local with_modules=( $* )
+
+	local m
+	local pattern="//"
+	for m in "${with_modules[@]}"; do
+		pattern+=" && /${m//\//\\/}/"
+	done
+
+	local -a versions
+	yaml_get_versions versions "${fname}" "${name}/${version}"
+	for v in "${versions[@]}"; do
+		local -i n_variants
+		yaml_get_num_variants n_variants "${fname}" "${v}"
+		(( n_variants == 0 )) && (( n_variants = 1 ))
+		local -i i
+		local -a deps=()
+		local -a build_requires=()
+		local relstage
+		local group
+		local ol_name
+		for (( i=0; i<n_variants; i++)); do
+			if [[ -z ${opt_overlay} ]]; then
+				yaml_get_overlay  ol_name  "${fname}" "${v}" $i
+			else
+				ol_name="${opt_overlay}"
+			fi
+			if [[ ! -v OverlayInfo[${ol_name}:inst_root] ]]; then
+				std::die 3 "Overlay is not defined -- ${ol_name}"
+			fi
+			mod_overlays[$i]="${ol_name}"
+		done
+
+		for (( i=0; i<n_variants; i++)); do
+			ol_name="${mod_overlays[$i]}"
+			yaml_get_relstage relstage "${fname}" "${v}" $i
+			yaml_get_dependencies deps "${fname}" "${v}" $i
+			yaml_get_build_requirements build_requires "${fname}" "${v}" $i
+			yaml_get_group group  "${fname}" "${v}" $i
+			pbuild.add_to_group "${group}"
+			# :FIXME:
+			# for the time being we prefix the build requirements
+			# with 'b:' and append them to the other dependencies.
+			# With this solution we don't have to change anything
+			# else in the code but have better readable variant
+			# files.
+			deps+=("${build_requires[@]/#/b:}")
+			declare ol_inst_root="${OverlayInfo[${ol_name}:inst_root]}"
+			declare ol_mod_root="${OverlayInfo[${ol_name}:mod_root]}"
+
+			local -a systems=()
+			local -a compilers=()
+			yaml_get_systems systems "${fname}" "${v}" $i
+			yaml_get_compilers compilers "${fname}" "${v}" $i
+			pbuild.supported_systems "${systems[@]}"
+			pbuild.supported_compilers "${compilers[@]}"
+			if (( ${#deps[@]} > 0 )); then
+				while read -a with_modules; do
+					pbuild.build_module_yaml \
+					     "${name}" "${v##*/}" \
+					     "${relstage}" "${with_modules[@]}"
+				done < <(bash_expand "" ${deps[@]}|${awk} "${pattern}")
+			else
+				pbuild.build_module_yaml \
+				     "${name}" "${v##*/}" \
+				     "${relstage}"
+			fi
+		done
+	done
+}
+
+build_modules() {
+	if [[ -n $(ls "${BUILDBLOCK_DIR}/files/"*.yaml 2>/dev/null) ]]; then
+		build_modules_yaml "$@"
+	else
+		build_modules_legacy "$@"
+	fi
+}
+
 #.............................................................................
 # main

 parse_args "$@"

-if [[ -z "${opt_system}" ]]; then
-        opt_system=$(std::get_os_release)
-fi
+opt_system="${opt_system:-$(std::get_os_release)}"

 pbuild.jobs "${opt_jobs}"
 pbuild.force_rebuild "${opt_force_rebuild}"
@@ -416,20 +674,17 @@ pbuild.update_modulefiles "${opt_update_modulefiles}"
 pbuild.system "${opt_system}"
 pbuild.verbose "${opt_verbose}"

-if [[ "${opt_bootstrap}" == 'yes' ]]; then
-        test -d "${BUILDBLOCK_DIR}/../../config" && PATH+=":$_"
-else
-        # Please note: if we trap DEBUG a statement like
-        #              test -d ... && PATH+=$_
-        #              does not work (at least on macOS with bash 4 and 5)
-        if [[ -d "${PMODULES_ROOT}/${PMODULES_CONFIG_DIR}" ]]; then
-                PATH+=":${PMODULES_ROOT}/${PMODULES_CONFIG_DIR}"
-        fi
-fi
-source "${opt_build_config}" || \
-        std::die 3 "Oops: Cannot source configuration file -- '$_'"
+#
+# read configuration for modbuild
+#
+pm::read_config

-: ${PMODULES_DISTFILESDIR:=${PMODULES_ROOT}/var/distfiles}
+# :FIXME: should dist files go to
+#         ${pm_root}/var/distfiles
+#         or
+#         ${overlay}/var/distfiles
+#         ?
+: ${PMODULES_DISTFILESDIR:="${PMODULES_HOME%%/Tools*}/var/distfiles"}
 : ${PMODULES_TMPDIR:=/var/tmp/${USER}}

 declare -r BUILD_SCRIPT
@@ -439,17 +694,6 @@ declare -r BUILDBLOCK_DIR
 IFS=/ read -r -a fname <<< "${BUILD_SCRIPT:1}"
 module_name=${fname[${#fname[@]}-2]}

-#
-# are we bootstrapping? If yes, go for it...
-#
-if [[ "${opt_bootstrap}" == 'yes' ]]; then
-	pbuild.bootstrap "${module_name}"  "${versions[0]}" 'stable'
-        exit $?
-fi
-
-#
-# else
-#
 for version in "${versions[@]}"; do
        build_modules "${module_name}" "${version}" "${opt_with_modules[@]}"
 done
@@ -10,9 +10,8 @@ Pmodules are a hierarchical module environment based on Environment Modules.
 "

 #
-# It might be that '${PMODULES_ROOT}/Tools/Pmodules/VERSION' is in PATH.
-# Why? With older version the PATH might have been set without loading
-# a module.
+# Older versions add '$PREFIX/bin' to PATH without loading Pmodules as
+# a module. Remove it ...
 #
 if { [module-info mode load] } {
    set PATH ":$::env(PATH):"
@@ -21,4 +20,9 @@ if { [module-info mode load] } {
    	    remove-path PATH $str
        }
    }
-}
+    remove-path C_INCLUDE_PATH "$PREFIX/include"
+    remove-path CPLUS_INCLUDE_PATH "$PREFIX/include"
+
+    set shell [module-info shell]
+    puts "source \"$PREFIX/init/$shell\""
+}
@@ -1,13 +1,15 @@
 #!/bin/bash
 #
-# The following settings are system defaults. They can be (re-)defined
-# in a system wide profile or in a user's profile.

 # set default version
 : ${PMODULES_VERSION:=@PMODULES_VERSION@}
+export PMODULES_VERSION

-declare -x PMODULES_ROOT=$(cd $(dirname "${BASH_SOURCE}")/.. && pwd)
-declare -x PMODULES_HOME="${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}"
+##### no changes below this line ######
+
+declare    __pm_root__=$(cd $(dirname "${BASH_SOURCE}")/.. && pwd)
+declare -x PMODULES_HOME="${__pm_root__}/Tools/Pmodules/${PMODULES_VERSION}"
+unset __pm_root__

 test -r "${PMODULES_HOME}/init/bash" && source "$_"

@@ -9,28 +9,8 @@ if ( ${PMODULES_VERSION} == "" ) then
 	setenv PMODULES_VERSION "@PMODULES_VERSION@"
 endif

-#############################################################################
-#          N O   C H A N G E S   B E L O W   T H I S   L I N E !            #
-#############################################################################
+setenv PMODULES_HOME "@PMODULES_ROOT@/Tools/Pmodules/${PMODULES_VERSION}"

-setenv PMODULES_MODULEFILES_DIR 'modulefiles'
-setenv ReleaseStages ':unstable:stable:deprecated:'
-
-setenv PMODULES_ROOT "@PMODULES_ROOT@"
-setenv PMODULES_CONFIG_DIR 'config'
-setenv PMODULES_HOME "${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}"
-setenv PMODULES_DIR "${PMODULES_HOME}"
-
-############################################################################
-# some sanity checks
-#
-
-# fixme: add some checks
-
-
-############################################################################
-# inititialize Pmodules for csh
-#
 set _init_csh="${PMODULES_HOME}/init/csh"
 if ( ! -r "${_init_csh}" ) then
 	echo "Oops: cannot initialize Modules!"
@@ -1,50 +1,20 @@
-#!/bin/bash
-#
-# Notes:
-#	- PMODULES_ROOT is derived from the location of this file.
-#	- Some for PMODULES_CONFIG_DIR.
-#	- The Pmodules software must be installed in
-#	  ${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}
+#!/bin/zsh
 #

-declare -xa DefaultGroups
-declare -xa DefaultReleaseStages
-declare -x  PMODULES_VERSION
-
-: ${DefaultGroups:=(Tools Programming)}
-: ${DefaultReleaseStages:=(stable)}
+# set default version
 : ${PMODULES_VERSION:=@PMODULES_VERSION@}

-#############################################################################
-#          N O   C H A N G E S   B E L O W   T H I S   L I N E !            #
-#############################################################################
+##### no changes below this line ######
+export PMODULES_VERSION

-declare -x PMODULES_MODULEFILES_DIR='modulefiles'
-declare -x ReleaseStages=':unstable:stable:deprecated:'
+declare    __this_file__=${(%):-%N}
+declare -x PMODULES_HOME="${__this_file____:h:h}/Tools/Pmodules/${PMODULES_VERSION}"
+unset __this_file__

-declare -x PMODULES_ROOT=$(cd $(dirname "${(%):-%N}")/.. && pwd)
-declare -x PMODULES_CONFIG_DIR=$(basename $(cd $(dirname "${(%):-%N}") && pwd))
-declare -x PMODULES_HOME="${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}"
-declare -x PMODULES_DIR="${PMODULES_HOME}"
-
-############################################################################
-# some sanity checks
-#
-if [[ ! -d ${PMODULES_ROOT} ]]; then 
-	echo "Oops: ${PMODULES_ROOT}: Set as Pmodules root, but this is not a directory." 1>&2
-	return 1
-fi
-if [[ ! -d ${PMODULES_HOME} ]]; then
-	echo "Oops: ${PMODULES_HOME}: Set as Pmodules home, but this is not a directory." 1>&2
-	return 1
-fi
-
-############################################################################
-# inititialize Pmodules for zsh
-#
 test -r "${PMODULES_HOME}/init/zsh" && source "$_"
-if (( $? != 0 )); then
-	echo "Oops: cannot initialize Pmodules environment!"
+
+if [[ $? != 0 ]]; then
+	echo "Oops: cannot initialize Pmodules!"
 	return 1
 fi

@@ -1,105 +1,19 @@
 #!/bin/zsh

-#############################################################################
-# implement module comand as function
+############################################################################
+# some sanity checks
 #
-module() {
-	local -r modulecmd="${PMODULES_HOME}/bin/modulecmd"
-
-	local -a args=()
-	local -a modulecmd_opts=()
-	local -a subcmd_opts=()
-
-	while (( $# > 0 )); do
-		case $1 in
-		-* )
-			modulecmd_opts+=( $1 )
-			shift
-			;;
-		* )
-			break
-			;;
-		esac
-	done
-	local -r subcmd="$1"
-	shift
-	while (( $# > 0 )); do
-		case $1 in
-		-* )
-			subcmd_opts+=( $1 )
-			;;
-		[/~a-zA-Z]* )
-			args+=( $1 )
-			;;
-		esac
-		shift
-	done
-
-	[[ -z ${subcmd} ]] && args+=( 'help' )
-	[[ ${#args[@]} == 0 ]] && args+=( '--' )
-
-	# Loop over all modules to load.
-	# Note: We have to eval here, otherwise we cannot do something like
-	# $ module load gcc/5.2.0 openmpi/1.8.8 hdf5/1.8.15
-	local m
-	for module in ${args[@]}; do
-		eval $( "${modulecmd}" zsh "${modulecmd_opts[@]}" "${subcmd}" \
-				       "${subcmd_opts[@]}" "${module}" )
-	done
-}
-export -f module
+if [[ ! -d ${PMODULES_HOME} ]]; then
+        echo "Oops: ${PMODULES_HOME}: Set as Pmodules home, but this is not a directory." 1>&2
+        return 1
+fi

 #############################################################################
-# helper functions
+# initialize zsh completion
 #
-save_env() {
-	local s=''
-	while (( $# > 0 )); do
-		s+="$( typeset -p $1 );"
-		shift
-	done
-	echo export PMODULES_ENV=$( "${PMODULES_HOME}/sbin/base64" --wrap=0 <<< "$s" )	
-}
-
-#############################################################################
-# setup environment
-#
-declare -x LOADEDMODULES=''
-declare -x _LMFILES_=''
-
-# build initial MODULEPATH
-declare -x MODULEPATH=''
-typeset -T MODULEPATH modulepath
-for group in ${DefaultGroups[@]}; do
-	dir="${PMODULES_ROOT}/${group}/${PMODULES_MODULEFILES_DIR}"
-	modulepath=( "${dir}" ${(m)modulepath:#${dir}} )
-done
-
-# build initial list of used releases
-declare -x UsedReleases=''
-typeset -T UsedReleases usedreleases
-for r in ${DefaultReleaseStages[@]}; do
-	usedreleases=( "${r}" ${(m)usedreleases:#${r}} )
-done
-
-eval $(save_env UsedReleases DefaultReleaseStages DefaultGroups ReleaseStages)
-
-unset UsedReleases
-unset DefaultReleaseStages
-unset DefaultGroups
-unset ReleaseStages
-
-# initialize MANPATH with output of `man --path` if not set
-[[ -z "${MANPATH}" ]] && manpath=$( man --path )
-
-# add man pages of Pmodules and remove all other Pmodules man pages
-manpath=( "${PMODULES_HOME}/share/man" ${(m)manpath:#${dirs_to_remove}} )
-
-# initialize completion
-test -r "${PMODULES_HOME}/init/zsh_completion" && source "$_"
-
-# cleanup
-unset group dir r dirs_to_remove
+#if [[ -r "${PMODULES_HOME}/init/bash_completion" ]]; then
+#	source "${PMODULES_HOME}/init/bash_completion"
+#fi

 #############################################################################
 # legacy...
@@ -107,6 +21,26 @@ unset group dir r dirs_to_remove
 unset MODULE_VERSION
 unset MODULE_VERSION_STACK
 unset MODULESHOME
+unset PMODULES_ENV
+
+declare -x PMODULES_DIR="${PMODULES_HOME}"
+
+
+#############################################################################
+# implement module comand as shell function
+#
+module() {
+	eval $("${PMODULES_HOME}/bin/modulecmd" bash "$@")
+}
+export -f module
+
+modbuild(){
+	(
+		eval $("${PMODULES_HOME}/bin/modulecmd" bash load System:bash)
+		"${PMODULES_HOME}/bin/modbuild" "$@"
+	)
+}
+export -f modbuild

 # Local Variables:
 # mode: sh
@@ -1,25 +0,0 @@
-#!/usr/bin/env modbuild
-
-pbuild::set_download_url "ftp://ftp.tcl.tk/pub/tcl/tcl8_6/tcl$V-src.tar.gz"
-pbuild::install_docfiles 'license.terms' 'README.md'
-
-pbuild::configure() {
-	case ${OS} in
-	Linux )
-		srcdir="${SRC_DIR}/unix"
-		;;
-	Darwin )
-		srcdir="${SRC_DIR}/macosx"
-		;;
-	esac
-	"${srcdir}"/configure \
-		--prefix="${PREFIX}" \
-		--bindir="${PREFIX}/${UTILBIN_DIR}" \
-		--enable-shared=no \
-		|| exit 1
-}
-
-pbuild::post_install() {
-	{ cd "${PREFIX}/${UTILBIN_DIR}" && rm -f tclsh && ln -fs tclsh${V%.*} tclsh; };
-}
-
@@ -1,5 +0,0 @@
-#!/usr/bin/env modbuild
-
-pbuild::set_download_url "https://ftp.gnu.org/gnu/$P/$P-$V.tar.gz"
-pbuild::add_configure_args "--bindir=${PREFIX}/${UTILBIN_DIR}" 
-
@@ -1,4 +0,0 @@
-#!/usr/bin/env modbuild
-
-pbuild::set_download_url "http://ftp.gnu.org/gnu/coreutils/$P-$V.tar.xz"
-pbuild::add_configure_args "--bindir=${PREFIX}/${UTILBIN_DIR}"
@@ -1,10 +0,0 @@
-#!/usr/bin/env pbuild
-
-pmodules.configure() {
-    "${MODULE_SRCDIR}"/configure \
-		      --prefix="${PREFIX}" \
-	|| exit 1
-}
-
-pmodules.add_to_group 'Tools'
-pmodules.make_all
@@ -1,4 +0,0 @@
-#!/usr/bin/env modbuild
-
-pbuild::set_download_url "https://ftp.gnu.org/pub/gnu/$P/$P-$V.tar.xz"
-pbuild::add_configure_args "--bindir=${PREFIX}/${UTILBIN_DIR}"
@@ -1,12 +0,0 @@
-diff -u getopt-1.1.6.orig//Makefile getopt-1.1.6/Makefile
--- getopt-1.1.6.orig//Makefile	2014-11-24 04:33:39.000000000 -0800
-+++ getopt-1.1.6/Makefile	2016-10-27 08:27:52.000000000 -0700
-@@ -61,7 +61,7 @@
- 	-$(RM) $(objects) $(binaries) 
- 
- getopt: $(objects)
-	$(CC) $(LDFLAGS) -o $@ $(objects)
-+	$(CC) -o $@ $(objects) $(LDFLAGS)
- 
- install: getopt install_po
- 	$(INSTALL) -m 755 -d $(DESTDIR)$(bindir) $(DESTDIR)$(man1dir)
@@ -1,54 +0,0 @@
-#!/usr/bin/env modbuild
-set -x
-
-pbuild::set_download_url "http://frodo.looijaard.name/system/files/software/getopt/getopt-1.1.6.tar.gz"
-pbuild::compile_in_sourcetree
-
-pbuild::pre_prep_Linux() {
-	pbuild::add_patch "Makefile.patch"
-}
-
-pbuild::configure() {
-	:
-}
-
-pbuild::compile() {
-	declare -x C_INCLUDE_PATH="${PREFIX}/include"
-	declare -x LIBRARY_PATH="${PREFIX}/lib"
-	case ${OS} in
-		Linux )
-			declare -x C_INCLUDE_PATH="${PREFIX}/include"
-			declare -x LIBRARY_PATH="${PREFIX}/lib"
-			declare -x LDFLAGS="-lintl -L${PREFIX}/lib"
-			;;
-		Darwin )
-			if [[ ! -d '/opt/local/bin' ]] || [[ ! -x '/opt/local/bin/msgfmt' ]]; then
-				std::die 1 "gettext port from Macports is required to build 'getopt'!"
-			fi
-			PATH+=':/opt/local/bin'
-			declare -x C_INCLUDE_PATH='/opt/local/include'
-			declare -x LDFLAGS="/opt/local/lib/libintl.a /opt/local/lib/libiconv.a -framework CoreFoundation"
-			;;
-	esac
-
-	make -e all || exit 1
-	declare -x DESTDIR="${PREFIX}"
-	declare -x prefix='' || exit 1 
-	PATH="${PREFIX}/${UTILBIN_DIR}:${PATH}"
-	make -e install
-	mv "${PREFIX}/bin/getopt" "${PREFIX}/${UTILBIN_DIR}"
-}
-
-pbuild::install() {
-	:
-}
-
-pbuild::cleanup_build() {
-	:
-}
-
-# Local Variables:
-# mode: sh
-# sh-basic-offset: 8
-# tab-width: 8
-# End:
@@ -1,19 +0,0 @@
-#!/usr/bin/env modbuild
-
-pbuild::set_download_url "https://ftp.gnu.org/pub/gnu/$P/$P-$V.tar.gz"
-
-pbuild::add_configure_args "--prefix=${PREFIX}"
-pbuild::add_configure_args "--bindir=${PREFIX}/${UTILBIN_DIR}"
-pbuild::add_configure_args "--disable-java"
-pbuild::add_configure_args "--disable-threads"
-pbuild::add_configure_args "--disable-shared"
-pbuild::add_configure_args "--enable-relocatable"
-pbuild::add_configure_args "--disable-openmp"
-pbuild::add_configure_args "--disable-acl"
-pbuild::add_configure_args "--disable-curses"
-pbuild::add_configure_args "--with-included-gettext"
-pbuild::add_configure_args "--without-libiconv-prefix"
-pbuild::add_configure_args "--without-libintl-prefix"
-pbuild::add_configure_args "--with-included-libxml"
-pbuild::add_configure_args "--with-pic=yes"
-
@@ -1,56 +0,0 @@
-#!/usr/bin/env modbuild
-
-# use system gcc to compile
-declare -rx CC=gcc
-
-pbuild::set_download_url "https://amas.web.psi.ch/Downloads/$P/$P-$V.tar.bz2"
-
-TCL_DIR="${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}"
-
-PATH="${TCL_DIR}/bin:${PATH}"
-
-pbuild::configure() {
-	case ${OS} in
-		Linux )
-			declare -x LIBS="-lz -lpthread"
-			;;
-		Darwin )
-			declare -x LIBS="-lz -framework CoreFoundation"
-			;;
-	esac
-	CPPFLAGS="-DUSE_INTERP_ERRORLINE" "${SRC_DIR}"/configure \
-		--prefix="${PREFIX}" \
-		--exec-prefix="${PREFIX}" \
-		--with-module-path="${PMODULES_ROOT}/Tools/${PMODULES_MODULEFILES_DIR}" \
-		--with-tcl="${TCL_DIR}/lib" \
-		--without-x \
-		--disable-versioning \
-		|| exit 1
-}
-
-pbuild::post_install() {
-	rm -v   "${PREFIX}/Modules/bin/add.modules"
-	rm -v   "${PREFIX}/Modules/bin/mkroot"
-	rm -rfv "${PREFIX}/Modules/modulefiles"
-	mv -v   "${PREFIX}/Modules/share/man/man1/module.1 ${PREFIX}/share/man/man1"
-	mv -v   "${PREFIX}/Modules/share/man/man4/modulefile.4 ${PREFIX}/share/man/man4"
-	rmdir   "${PREFIX}/Modules/bin"
-	rmdir   "${PREFIX}/Modules/share/man/man1"
-	rmdir   "${PREFIX}/Modules/share/man/man4"
-	rmdir   "${PREFIX}/Modules/share/man"
-	rmdir   "${PREFIX}/Modules/share"
-	rmdir   "${PREFIX}/Modules"
-	rm -f	"${PREIX}/init/{ksh,perl.pm,python.py,ruby.rb,cmake,.modulespath}"
-	cp -v   "${BUILD_DIR}/modulecmd" "${PREFIX}/libexec/modulecmd.bin" || exit 1
-}
-	
-# fake module command
-module() {
-    :
-}
-
-# Local Variables:
-# mode: sh
-# sh-basic-offset: 8
-# tab-width: 8
-# End:
@@ -1,5 +0,0 @@
-#!/usr/bin/env modbuild
-
-pbuild::set_download_url "https://core.tcl-lang.org/tcllib/uv/$P-$V.tar.xz"
-
-
@@ -1,48 +1,84 @@
 #!/usr/bin/env bash
 #
-if [ "${BASH_VERSINFO[0]}" -lt 4 ]; then
-	echo "BASH version >= 4 is required and must be available in PATH!" 1>&2
+
+declare -rx VERSION='1.1.10'
+
+if (( "${BASH_VERSINFO[0]}" < 5 )); then
+	echo "BASH version 5.0 or newer is required and must be available in PATH!" 1>&2
 	exit 1
 fi

-declare -r OS=$(uname -s)
+set -o nounset
+set -o pipefail
+shopt -s nullglob

-declare	BOOTSTRAP_DIR=$(dirname "$0")
-source "${BOOTSTRAP_DIR}/Pmodules/libstd.bash" || { echo "Oops!" 1>&2; exit 42; }
-
-declare -r BOOTSTRAP_DIR=$(std::get_abspath "${BOOTSTRAP_DIR}")
+declare -r BOOTSTRAP_DIR="$(cd "$(dirname "$0")" && pwd -P)"
 declare -r SRC_DIR="${BOOTSTRAP_DIR}/Pmodules"

-# these variables need to be defined but must be initialized with an empty string
-declare -x PMODULES_HOME=''
-declare -x PMODULES_DISTFILESDIR=''
-declare -x PMODULES_TMPDIR=''
+source "${SRC_DIR}/libstd.bash"		|| { echo "Oops!" 1>&2; exit 42; }
+source "${SRC_DIR}/libpbuild.bash"	|| { echo "Oops!" 1>&2; exit 42; }

+declare -r  PMOD_DIR="Tools/Pmodules/${VERSION}"
+# config directory and file relative to install root
 declare -rx CONFIG_DIR='config'
-declare -rx CONFIG_FILE='modbuild.conf'
-
-# defaults
-declare -rx DEFAULT_PMODULES_ROOT='/opt/psi'
-declare -rx DEFAULT_DISTFILES_DIR="var/distfiles"
-declare -rx DEFAULT_VERSIONS_CONFIG="${CONFIG_DIR}/versions.conf"
-declare -rx DEFAULT_TMPDIR='var/tmp/${USER}'
+declare -rx CONFIG_FILE="${CONFIG_DIR}/Pmodules.yaml"

 # directory where the required tools will be installed (like bash, tclsh, etc)
 declare -rx UTILBIN_DIR='libexec'

+# defaults
+declare -rx DEFAULT_INSTALL_ROOT='/opt/psi'
+declare -rx DEFAULT_DISTFILES_DIR='var/distfiles'
+declare -rx DEFAULT_TMP_DIR='var/tmp/${USER}'
+
 #-----------------------------------------------------------------------------
 #
-get_version() {
-	local -r name="$1"
-	echo $(awk "/^$1[[:blank:]]/ {print \$2}" "${DEFAULT_VERSIONS_CONFIG}")
+read_config_file() {
+	local fname="$1"
+	if [[ ! -r "${fname}" ]]; then
+		std::die 1 "Configuration file '${fname}' does not exist or is not readable!"
+	fi
+
+	eval $(std::parse_yaml "${fname}" '') || \
+		std::die 1 "Cannot read configuration file '${fname}'"
+
+	declare -xg INSTALL_ROOT="${Overlays_base_install_root}"
+	if [[ -z "${INSTALL_ROOT}" ]]; then
+		std::die 1 "Error in configuration file '${fname}': install root not defined!"
+	fi
+	declare -xg PREFIX="${INSTALL_ROOT}/${PMOD_DIR}"
+	declare -xg DOWNLOADS_DIR="${DistfilesDir:-${INSTALL_ROOT}/${DEFAULT_DISTFILES_DIR}}"
+	declare -xg TMP_DIR="${TmpDir:-${INSTALL_ROOT}/${DEFAULT_TMP_DIR}}"
 }

-declare -rx PMODULES_VERSION=$(get_version 'Pmodules')
+#-----------------------------------------------------------------------------
+# The next functions are used in the sub-commands, if an illegal option
+# or argument has been passed.
+#
+illegal_option(){
+	local subcmd="$1"
+	local opt="$2"
+	std::die 1 \
+		 "%s: %s -- %s" \
+		 "$(basename $0) ${subcmd}" \
+		 "Illegal option" \
+		 "${opt}"
+}
+
+illegal_arg(){
+	local subcmd="$1"
+	local arg="$2"
+	std::die 1 \
+		 "%s: %s -- %s" \
+		 "$(basename $0) ${subcmd}" \
+		 "Illegal argument" \
+		 "${arg}"
+}

 #-----------------------------------------------------------------------------
-#
-usage() {
-	local prog=$(basename $0)
+# help for sub-command 'help' (usage)
+build::help_help(){
+	local prog="$(basename "$0")"
 	echo "
 Usage: ${prog} help|configure|compile|install

@@ -65,59 +101,36 @@ to get help for a specific sub-command.
 }

 #-----------------------------------------------------------------------------
+# sub-command 'help'
 #
-pmodules::help() {
-	if (( $# > 1 )); then
-		usage
+# print help for sub-commands
+#
+build::help() {
+	if (( $# == 0 )); then
+		build::help_help
+	else
+		case $1 in
+			configure|compile|install )
+				build::help_$1
+				;;
+			help )
+				build::help_help
+				;;
+			-* )
+				illegal_option 'help' "$1"
+				;;
+			* )
+				std::error "No such command -- $1"
+				build::help_help
+				;;
+		esac
 	fi
-	case $1 in
-		configure|compile|install )
-			pmodules::help_$1
-			;;
-		* )
-			echo -en "$1 - invalid sub-command!\n" 1>&2
-			usage
-			;;
-	esac
 }

 #-----------------------------------------------------------------------------
+# help for sub-command 'configure'
 #
-read_config_file() {
-	local var="$1"
-	local fname="${!var}"
-	if [[ ! -r "${fname}" ]]; then
-		std::die 1 "Configuration file '${fname}' does not exist or is not readable!"
-	fi
-
-	source "${fname}" || std::die 1 "Cannot read configuration file '${fname}'"
-
-	if [[ -z "${PMODULES_ROOT}" ]]; then
-		std::die 1 "Error in configuration file '${fname}': PMODULE_ROOT not defined!"
-	fi
-	if [[ -z "${PMODULES_VERSION}" ]]; then
-		std::die 1 "Error in configuration file '${fname}': PMODULE_VERSION not defined!"
-	fi
-	if [[ -z "${PMODULES_DISTFILESDIR}" ]]; then
-		std::die 1 "Error in configuration file '${fname}': PMODULES_DISTFILESDIR not defined!"
-	fi
-	if [[ -z "${PMODULES_TMPDIR}" ]]; then
-		std::die 1 "Error in configuration file '${fname}': PMODULE_TMPDIR not defined!"
-	fi
-
-	# we have to make these variables global, otherwise they are not set
-	# in the calling function
-	declare -g PMODULES_ROOT="${PMODULES_ROOT}"
-	declare -g PMODULES_HOME="${PMODULES_HOME}"
-	declare -g PMODULES_DISTFILESDIR="${PMODULES_DISTFILESDIR}"
-	declare -g PMODULES_TMPDIR="${PMODULES_TMPDIR}"
-
-	std::upvar "${var}" "${fname}"
-}
-
-#-----------------------------------------------------------------------------
-#
-pmodules::help_configure() {
+build::help_configure() {
 	echo "
 Usage: $(basename $0) configure [OPTION...]

@@ -125,21 +138,24 @@ Configure and setup a new Pmodules environment. You need permissions
 to write to the installation root.

 Options:
--prefix=DIR
+--install_root=DIR
 	Root of the Pmodules environment installation. Everything will be
 	installed in a directory hierarchy with 'DIR' as prefix.
-       	The default is '${DEFAULT_PMODULES_ROOT}'.
+       	The default is '${DEFAULT_INSTALL_ROOT}'.

 --distfilesdir=DIR
 	Directory where downloaded files are stored.
-	The default is '${DEFAULT_PMODULES_DISTFILESDIR}' in the 
+	The default is '${DEFAULT_INSTALL_ROOT}/${DEFAULT_DISTFILES_DIR}' in the 
 	Pmodules root directory.

 --tmpdir=DIR
 	Directory for temporary files.
-	The default is '${DEFAULT_PMODULES_TMPDIR}'
+	The default is '${DEFAULT_INSTALL_ROOT}/${DEFAULT_TMP_DIR}'

--help
+--force|-f
+	Override existing configuration.
+
+--help|-h|-?
 	Print this help text.

 " 1>&2
@@ -147,102 +163,123 @@ Options:
 }

 #-----------------------------------------------------------------------------
+# sub-command 'configure'
 #
-pmodules::configure() {
-	local prefix="${PMODULES_ROOT:-${DEFAULT_PMODULES_ROOT}}"
-	local distfilesdir=''
-	local tmpdir=''
-	local config_file=''
+# Create basic directory hierachy and the configuration file in the given
+# installation root directory
+#
+build::configure() {
 	local opt_force='no'

 	while (( $# > 0 )); do
 		case "$1" in
-			--prefix )
-				prefix="$2"
-				shift 1
-				;;
-			--prefix=* )
-				prefix="${1#*=}"
+			--install_root | --install_root=* )
+				if [[ $1 == *=* ]]; then
+					INSTALL_ROOT="${1#*=}"
+				else
+					INSTALL_ROOT="$2"
+					shift 1
+				fi
 				;;
 			--distfilesdir )
-				distfilesdir="$2"
-				shift 1
-				;;
-			--distfilesdir=* )
-				distfilesdir="${1#*=}"
+				if [[ $1 == *=* ]]; then
+					DOWNLOADS_DIR="${1#*=}"
+				else
+					DOWNLOADS_DIR="$2"
+					shift 1
+				fi
 				;;
 			-f | --force )
 				opt_force='yes'
 				;;
-			--tmpdir )
-				tmpdir="$2"
-				shift 1
-				;;
-			--tmpdir=* )
-				tmpdir="${1#*=}"
+			--tmpdir | --tmpdir=* )
+				if [[ $1 == *=* ]]; then
+					TMP_DIR="${1#*=}"
+				else
+					TMP_DIR="$2"
+					shift 1
+				fi
 				;;
 			--help | -h | -\? )
-				pmodules::help_configure
+				build::help_configure
 				;;
 			-* )
-				std::die 1 "$1: illegal option"
+				illegal_option 'configure' "$1"
 				;;
 			* )
-				std::die 1 "$1: illegal argument to sub-command 'configure'."
+				illegal_arg 'configure' "$1"
 				;;
 		esac
 		shift 1
 	done
-	if [[ ! -d ${prefix} ]]; then
-		echo "The root directory '${prefix}' does not exist, trying to create it..."
-		if ! mkdir -p "${prefix}"; then
-			std::die 1 "Creating the root directory failed!\nAborting..."
+	: ${INSTALL_ROOT:=${DEFAULT_INSTALL_ROOT}}
+	: ${DOWNLOADS_DIR:=${INSTALL_ROOT}/${DEFAULT_DISTFILES_DIR}}
+	: ${TMP_DIR:=${INSTALL_ROOT}/${DEFAULT_TMP_DIR}}
+	PREFIX="${INSTALL_ROOT}/${PMOD_DIR}"
+
+	#---
+	# check/create the install root
+	if [[ ! -d ${INSTALL_ROOT} ]]; then
+		std::info "%s\n%s" \
+			  "The root directory '${INSTALL_ROOT}' does not exist!" \
+			  "Trying to create it..."
+		if ! mkdir -p "${INSTALL_ROOT}"; then
+			std::die 1 "%s\n%s" \
+				 "Creating the root directory failed!" \
+				 "Aborting..."
 		fi
 	fi
-	if [[ ! -w ${prefix} ]]; then
-		std::die 1 "The root directory '${prefix}' is not writable!\nAborting..."
+	if [[ ! -w ${INSTALL_ROOT} ]]; then
+		std::die 1 "%s\n%s" \
+			 "The root directory '${INSTALL_ROOT}' is not writable!" \
+			 "Aborting..."
 	fi
-	mkdir -p "${prefix}/${CONFIG_DIR}" || \
+
+	#---
+	# check/create YAML config file in install root
+	mkdir -p "${INSTALL_ROOT}/${CONFIG_DIR}" || \
 		std::die 1 "Aborting..."

-	local config_file="${prefix}/${CONFIG_DIR}/${CONFIG_FILE}"
-	if [[ "${opt_force}" == 'yes' ]]; then
-		rm -f "${config_file}"
+	local config_file="${INSTALL_ROOT}/${CONFIG_FILE}"
+	if [[ "${opt_force}" != 'yes' ]] && [[ -e "${config_file}" ]]; then
+		std::die 1 "%s\n%s" \
+			 "The Pmodules environment in '${INSTALL_ROOT}' has already been configured!" \
+			 "Use the option --force to override. Aborting..."
 	fi

-	if [[ -e "${config_file}" ]]; then
-		std::die 1 "The Pmodules environment has already been configured!
-Use the option --force to override.\nAborting..."
-	fi
-
-	[[ -z "${distfilesdir}" ]] && distfilesdir="${prefix}/${DEFAULT_DISTFILES_DIR}"
-	[[ -z "${tmpdir}" ]] && tmpdir="${prefix}/${DEFAULT_TMPDIR}"
-
-	sed_cmd="s:@PMODULES_ROOT@:${prefix}:g;"
-	sed_cmd+="s:@PMODULES_DISTFILESDIR@:${distfilesdir}:g;"
-	sed_cmd+="s:@PMODULES_TMPDIR@:${tmpdir}:g;"
-        sed_cmd+="s:@PMODULES_VERSION@:${PMODULES_VERSION}:g"
+	sed_cmd="s:@INSTALL_ROOT@:${INSTALL_ROOT}:g;"
+	sed_cmd+="s:@PMODULES_DISTFILESDIR@:${DOWNLOADS_DIR}:g;"
+	sed_cmd+="s:@PMODULES_TMPDIR@:${TMP_DIR}:g;"
+        sed_cmd+="s:@PMODULES_VERSION@:${VERSION}:g"
        
-	sed "${sed_cmd}" "${BOOTSTRAP_DIR}/${CONFIG_DIR}/${CONFIG_FILE}.in" \
+	sed "${sed_cmd}" "${BOOTSTRAP_DIR}/${CONFIG_FILE}.in" \
 		> "${config_file}" || \
 		std::die 1 "Cannot create configuration file in Pmodules root\nAborting..."

-	read_config_file 'config_file'
-	install -d -m 0755 "${PMODULES_HOME}/bin"
-	install -d -m 0755 "${PMODULES_HOME}/init"
-	install -d -m 0755 "${PMODULES_HOME}/lib"
-	install -d -m 0755 "${PMODULES_HOME}/libexec"
+	#---
+	# create basic directories
+	install -d -m 0755 \
+		"${INSTALL_ROOT}/Tools/modulefiles/Pmodules" \
+		"${INSTALL_ROOT}/Libraries/modulefiles" \
+		"${INSTALL_ROOT}/Programming/modulefiles" \
+		"${DOWNLOADS_DIR}" || \
+		std::die 1 "%s" \
+			 "Creating basic directories failed\n" \
+			 "Aborting..."
+
+	#---
 	echo "Configuration:"
-	echo "  root of Pmodules environment: ${prefix}"
-	echo "  Pmodule prefix:               ${PMODULES_HOME}"
-	echo "  tmp directory:                ${tmpdir}"
-	echo "  store for downloaded files:   ${distfilesdir}"
+	echo "  root of Pmodules environment: ${INSTALL_ROOT}"
+	echo "  Pmodule prefix:               ${PREFIX}"
+	echo "  tmp directory:                ${TMP_DIR}"
+	echo "  store for downloaded files:   ${DOWNLOADS_DIR}"
 	echo "Done..."
 }

 #-----------------------------------------------------------------------------
+# help for sub-command 'compile'
 #
-pmodules::help_compile() {
+build::help_compile() {
 	echo "
 Usage: $(basename $0) compile [OPTION...]

@@ -250,22 +287,14 @@ Compile and install the required tools for a new Pmodules environment.
 ou need the permissions to write to the installation root.

 Options:
--prefix=DIR
-	Root of the Pmodules environment installation. The root of the
-       	installation must be either specified via this option or the
-	environment variable PMODULES_ROOT. If this option is used and
-	the PMODULES_ROOT is set, the directory specified with this 
-	option will be used.
+--install_root=DIR
+	Root of the Pmodules environment installation. Everything will be
+	installed in a directory hierarchy with 'DIR' as prefix.
+       	The default is '${DEFAULT_INSTALL_ROOT}'.

--debug
-	Enable verbose/debug output.
-
--disable-cleanup )
+--disable-cleanup
 	Do not cleanup the tmp directory after compilation and installation.

--force | -f
-	Force compilation.
-
 --help
 	Print this help text.

@@ -273,266 +302,208 @@ Options:
 	std::die 1 ""
 }

-pmodules::compile() {
-	build () {
-		local -r name="$1"
-		local -r version=$(get_version "${name}")
-		shift
-
-		"${BOOTSTRAP_DIR}/Pmodules/modbuild.in" \
-			"--config=${config_file}" \
-			"--enable-cleanup" \
-			"--force-rebuild" \
-			"--debug" \
-			"--verbose" \
-			"${BOOTSTRAP_DIR}/Tools/${name}/build" \
-			"${build_opts[@]}" "$@" "${version}" || \
-			std::die 3 "Compiling '${name}' failed!"
-	}
-
-	local prefix="${PMODULES_ROOT:-${DEFAULT_PMODULES_ROOT}}"
+#-----------------------------------------------------------------------------
+# sub-command 'compile'
+#
+# compile all required tools like bash, tclsh etc for a Pmodules module.
+# The version is defined at the beginning of this file.
+#
+build::compile() {
 	local opt_force='no'
-	local config_file=''
+	local opt_cleanup='yes'

 	while (( $# > 0 )); do
 		case $1 in
-			--prefix )
-				prefix="$2"
-				shift 1
-				;;
-			--prefix=* )
-				prefix="${1#*=}"
+			--install_root | --install_root=* )
+				if [[ $1 == *=* ]]; then
+					INSTALL_ROOT="${1#*=}"
+				else
+					INSTALL_ROOT="$2"
+					shift 1
+				fi
 				;;
 			--disable-cleanup )
-				build_opts+=( "$1" )
-				;;
-			--debug )
-				build_opts+=( "$1" )
-				;;
-			-f | --force )
-				opt_force='yes'
+				opt_cleanup='no'
 				;;
 			--help | -h | -\? )
-				pmodules::help_compile
+				build::help_compile
 				;;
 			-* )
-				std::die 1 "$1: illegal option"
+				illegal_option 'compile' "$1"
 				;;
 			* )
-				std::die 1 "$1: illegal argument for  sub-command 'compile'."
+				illegal_arg 'compile' "$1"
 				;;
 		esac
 		shift 1
 	done
+	: ${INSTALL_ROOT:=${DEFAULT_INSTALL_ROOT}}
+	PREFIX="${INSTALL_ROOT}/${PMOD_DIR}"

-	local config_file="${prefix}/${CONFIG_DIR}/${CONFIG_FILE}"
-	read_config_file config_file
-	install -d -m 0755 "${PMODULES_HOME}/bin"
-	install -d -m 0755 "${PMODULES_HOME}/init"
-	install -d -m 0755 "${PMODULES_HOME}/lib"
-	install -d -m 0755 "${PMODULES_HOME}/libexec"
+	read_config_file "${INSTALL_ROOT}/${CONFIG_FILE}"

 	echo "Configuration:"
-	echo "  root of Pmodules environment: ${prefix}"
-	echo "  Pmodule prefix:               ${PMODULES_HOME}"
+	echo "  root of Pmodules environment: ${INSTALL_ROOT}"
+	echo "  Pmodule prefix:               ${PREFIX}"

-	#if [[ ! -f "${PMODULES_HOME}/${UTILBIN_DIR}/base64" ]] || [[ ${opt_force} == 'yes' ]]; then
-	#	build coreutils
-	#fi
+	install -m 0755 -d "${PREFIX}"/{bin,init,lib,libexec} \

-	if [[ "${OS}" == 'Darwin' ]]; then
-		if [[ ! -f "${PMODULES_HOME}/${UTILBIN_DIR}/getopt" ]] || [[ ${opt_force} == 'yes' ]]; then
-			build getopt
-		fi
-
-		if [[ ! -f "${PMODULES_HOME}/${UTILBIN_DIR}/find" ]] || [[ ${opt_force} == 'yes' ]]; then
-			build findutils
-		fi
+	for recipe in recipes/[0-9]*; do
+		"./${recipe}" "${PREFIX}"
+	done
+	if [[ "${opt_cleanup}" == 'yes' ]]; then
+		rm -rf "${TMP_DIR}/*"
+		rm -f  "${PREFIX}/lib/libtcl*.a"
+		rm -rf "${PREFIX}/include"
 	fi
-
-	if [[ ! -f "${PMODULES_HOME}/${UTILBIN_DIR}/bash" ]] || [[ ${opt_force} == 'yes' ]]; then
-		build bash
-	fi
-
-	if [[ ! -e "${PMODULES_HOME}/${UTILBIN_DIR}/tclsh" ]] || [[ ${opt_force} == 'yes' ]]; then
-		build Tcl
-	fi
-
-	if [[ ! -e "${PMODULES_HOME}/lib/tcllib1.20" ]] || [[ ${opt_force} == 'yes' ]]; then
-		build tcllib
-	fi
-
-	if [[ ! -e "${PMODULES_HOME}/libexec/modulecmd.bin" ]] || [[ ${opt_force} == 'yes' ]]; then
-		build modules
-	fi
-	rm -rf "${PMODULES_HOME}/include"
-	rm -rf "${PMODULES_HOME}/lib/"*.a
-	rm -rf "${PMODULES_HOME}/lib/"*.la
-	rm -rf "${PMODULES_HOME}/lib/bash"
-	rm -rf "${PMODULES_HOME}/lib/pkginfo"
-	rm -rf "${PMODULES_HOME}/man"
-	rm -rf "${PMODULES_HOME}/share"
-
 	echo "Done..."
 }

 #-----------------------------------------------------------------------------
+# help for sub-command 'install'
 #
-pmodules::help_install() {
+build::help_install() {
 	echo "
 Usage: $(basename $0) install [OPTION...]

 Install a new Pmodules version.

 Options:
--prefix=DIR
-	Root of the Pmodules environment installation. The root of the
-       	installation must be either specified via this option or the
-	environment variable PMODULES_ROOT. If this option is used and
-	the PMODULES_ROOT is set, the directory specified with this 
-	option will be used.
+--install_root=DIR
+	Root of the Pmodules environment installation. Everything will be
+	installed in a directory hierarchy with 'DIR' as prefix.
+       	The default is '${DEFAULT_INSTALL_ROOT}'.

 --debug
 	Enable verbose/debug output.

--disable-cleanup )
-	Do not cleanup the tmp directory after compilation and installation.
-
--force | -f
-	Force compilation.
-
--help
+--help|-h|-?
 	Print this help text.

 " 1>&2
 	std::die 1 ""
 }

-pmodules::install() {
-	local prefix="${PMODULES_ROOT:-${DEFAULT_PMODULES_ROOT}}"
-	local config_file=''
-	local opt_force='no'
-
+#-----------------------------------------------------------------------------
+# sub-command 'install'
+#
+# Install Pmodules files.
+#
+build::install() {
 	while (( $# > 0 )); do
 		case $1 in
 			--debug )
 				set -x
 				;;
-			--prefix )
-				prefix="$2"
-				shift 1
-				;;
-			--prefix=* )
-				prefix="${1#*=}"
-				;;
-			-f | --force )
-				opt_force='yes'
+			--install_root | --install_root=* )
+				if [[ $1 == *=* ]]; then
+					INSTALL_ROOT="${1#*=}"
+				else
+					INSTALL_ROOT="$2"
+					shift 1
+				fi
 				;;
 			--help | -h | -\? )
-				pmodules::help_install
+				build::help_install
 				;;
 			-* )
-				std::die 1 "$1: illegal option"
+				illegal_option 'install' "$1"
 				;;
 			* )
-				std::die 1 "$1: illegal argument to sub-command 'install'."
+				illegal_arg 'install' "$1"
 				;;
 		esac
 		shift 1
 	done

-	local config_file="${prefix}/${CONFIG_DIR}/${CONFIG_FILE}"
-	read_config_file 'config_file'
+	: ${INSTALL_ROOT:=${DEFAULT_INSTALL_ROOT}}
+	PREFIX="${INSTALL_ROOT}/${PMOD_DIR}"
+
+	read_config_file "${INSTALL_ROOT}/${CONFIG_FILE}"

 	###
 	#
 	# begin installation
 	#
 	echo "Configuration:"
-	echo "  root of Pmodules environment: ${PMODULES_ROOT}"
-	echo "  Pmodule prefix:               ${PMODULES_HOME}"
-	sed_cmd="s:@PMODULES_HOME@:${PMODULES_HOME}:g;"
-	sed_cmd+="s:@PMODULES_VERSION@:${PMODULES_VERSION}:g;"
-	sed_cmd+="s:@MODULES_VERSION@:${MODULES_VERSION}:g;"
-	sed_cmd+="s:@PMODULES_DISTFILESDIR@:${PMODULES_DISTFILESDIR}:g;"
-	sed_cmd+="s:@PMODULES_TMPDIR@:${PMODULES_TMPDIR}:g;"
-	sed_cmd+="s:@TCLSHDIR@:${PMODULES_HOME}/${UTILBIN_DIR}:g;"
-	sed_cmd+="s:@pager@::g;"
-	sed_cmd+="s:@pageropts@::g;"
-	sed_cmd+="s:@etcdir@:${PMODULES_ROOT}/${CONFIG_DIR}:g;"
+	echo "  root of Pmodules environment: ${INSTALL_ROOT}"
+	echo "  Pmodule prefix:               ${PREFIX}"
+	sed_cmd+="s:@PMODULES_VERSION@:${VERSION}:g;"
 	sed_cmd+="s:@VERSIONING@:#:g;"
-	sed_cmd+="s:@prefix@:${PMODULES_HOME}:g;"
-	sed_cmd+="s:@initdir@:${PMODULES_HOME}/init:g;"
-	sed_cmd+="s:@MODULES_RELEASE@:${PMODULES_VERSION}:g;"
-	sed_cmd+="s:@BASH@:${PMODULES_HOME}/${UTILBIN_DIR}/bash:g;"
-	sed_cmd+="s:@MODULECMD@:${PMODULES_HOME}/${UTILBIN_DIR}/modulecmd.bash:g;"
-	sed_cmd+="s:@MODMANAGE@:${PMODULES_HOME}/${UTILBIN_DIR}/modmanage.bash:g;"
+	sed_cmd+="s:@BASH@:${PREFIX}/${UTILBIN_DIR}/bash:g;"
+	sed_cmd+="s:@MODULECMD@:${PREFIX}/${UTILBIN_DIR}/modulecmd.bash:g;"
+
+	sed "${sed_cmd}" "${SRC_DIR}/profile.bash.in" \
+	    > "${INSTALL_ROOT}/${CONFIG_DIR}/profile.bash-${VERSION}"
+	sed "${sed_cmd}" "${SRC_DIR}/profile.csh.in" \
+	    > "${INSTALL_ROOT}/${CONFIG_DIR}/profile.csh-${VERSION}"
+	sed "${sed_cmd}" "${SRC_DIR}/profile.zsh.in" \
+	    > "${INSTALL_ROOT}/${CONFIG_DIR}/profile.zsh-${VERSION}"
+	chmod 0644 "${INSTALL_ROOT}/${CONFIG_DIR}"/*-${VERSION}
+
+	test -e "${INSTALL_ROOT}/${CONFIG_DIR}/profile.bash" || \
+		install -m 0644 "$_-${VERSION}" "$_"
+
+	test -e "${INSTALL_ROOT}/${CONFIG_DIR}/profile.csh" || \
+		install -m 0644 "$_-${VERSION}" "$_"
+
+	test -e "${INSTALL_ROOT}/${CONFIG_DIR}/profile.zsh" || \
+		install -m 0644 "$_-${VERSION}" "$_"
+
+	sed "${sed_cmd}" "${SRC_DIR}/modulecmd.in" \
+            > "${PREFIX}/bin/modulecmd"
+	chmod 0755 "${PREFIX}/bin/modulecmd"
+	sed "${sed_cmd}" "${SRC_DIR}/modulecmd.bash.in" \
+	    > "${PREFIX}/libexec/modulecmd.bash"
+	chmod 0755 "${PREFIX}/libexec/modulecmd.bash"
+	sed "${sed_cmd}" "${SRC_DIR}/modulecmd.tcl.in" \
+	    > "${PREFIX}/libexec/modulecmd.tcl"
+	chmod 0755 "${PREFIX}/libexec/modulecmd.tcl"
+
+	sed "${sed_cmd}" "${SRC_DIR}/libpmodules.bash.in" \
+	    > "${PREFIX}/lib/libpmodules.bash"
+	chmod 0755 "${PREFIX}/lib/libpmodules.bash"
+
+        sed "${sed_cmd}" "${SRC_DIR}/modbuild.in" \
+            > "${PREFIX}/bin/modbuild"
+	chmod 0755 "${PREFIX}/bin/modbuild"
+
+	sed "${sed_cmd}" "${SRC_DIR}/modmanage.in" \
+            > "${PREFIX}/bin/modmanage"
+	chmod 0755 "${PREFIX}/bin/modmanage"
+	sed "${sed_cmd}" "${SRC_DIR}/modmanage.bash.in" \
+	    > "${PREFIX}/libexec/modmanage.bash"
+	chmod 0755 "${PREFIX}/libexec/modmanage.bash"
+
+	test -e "${INSTALL_ROOT}/${CONFIG_FILE}" || \
+		install -m 0644 "$_"			"${INSTALL_ROOT}/${CONFIG_DIR}"
 	
-	sed "${sed_cmd}" "${SRC_DIR}/profile.bash.in"     > "${PMODULES_ROOT}/${CONFIG_DIR}/profile.bash-${PMODULES_VERSION}"
-	sed "${sed_cmd}" "${SRC_DIR}/profile.csh.in"      > "${PMODULES_ROOT}/${CONFIG_DIR}/profile.csh-${PMODULES_VERSION}"
-	sed "${sed_cmd}" "${SRC_DIR}/profile.zsh.in"      > "${PMODULES_ROOT}/${CONFIG_DIR}/profile.zsh-${PMODULES_VERSION}"
-	chmod 0644 "${PMODULES_ROOT}/${CONFIG_DIR}"/*-${PMODULES_VERSION}
+	install -m 0755 "${SRC_DIR}/yq.$(uname -m)_$(uname -s)"	"${PREFIX}/libexec/yq"
+	install -m 0644 "${SRC_DIR}/bash"		"${PREFIX}/init"
+	install -m 0644 "${SRC_DIR}/bash_completion"	"${PREFIX}/init"
+	install -m 0644 "${SRC_DIR}/csh"		"${PREFIX}/init"
+	install -m 0644 "${SRC_DIR}/zsh"		"${PREFIX}/init"

-	test -e "${PMODULES_ROOT}/${CONFIG_DIR}/profile.bash" || \
-		install -m 0644 "$_-${PMODULES_VERSION}" "$_"
-
-	test -e "${PMODULES_ROOT}/${CONFIG_DIR}/profile.csh" || \
-		install -m 0644 "$_-${PMODULES_VERSION}" "$_"
-
-	test -e "${PMODULES_ROOT}/${CONFIG_DIR}/profile.zsh" || \
-		install -m 0644 "$_-${PMODULES_VERSION}" "$_"
-
-	sed "${sed_cmd}" "${SRC_DIR}/modulecmd.in"        > "${PMODULES_HOME}/bin/modulecmd"
-	chmod 0755 "${PMODULES_HOME}/bin/modulecmd"
-	sed "${sed_cmd}" "${SRC_DIR}/modulecmd.bash.in"   > "${PMODULES_HOME}/libexec/modulecmd.bash"
-	chmod 0755 "${PMODULES_HOME}/libexec/modulecmd.bash"
-	sed "${sed_cmd}" "${SRC_DIR}/modulecmd.tcl.in"    > "${PMODULES_HOME}/libexec/modulecmd.tcl"
-	chmod 0755 "${PMODULES_HOME}/libexec/modulecmd.tcl"
-
-	sed "${sed_cmd}" "${SRC_DIR}/libpmodules.bash.in"    > "${PMODULES_HOME}/lib/libpmodules.bash"
-	chmod 0755 "${PMODULES_HOME}/lib/libpmodules.bash"
-
-        sed "${sed_cmd}" "${SRC_DIR}/modbuild.in"         > "${PMODULES_HOME}/bin/modbuild"
-	chmod 0755 "${PMODULES_HOME}/bin/modbuild"
-
-	sed "${sed_cmd}" "${SRC_DIR}/modmanage.in"        > "${PMODULES_HOME}/bin/modmanage"
-	chmod 0755 "${PMODULES_HOME}/bin/modmanage"
-	sed "${sed_cmd}" "${SRC_DIR}/modmanage.bash.in"   > "${PMODULES_HOME}/libexec/modmanage.bash"
-	chmod 0755 "${PMODULES_HOME}/libexec/modmanage.bash"
-
-	test -e "${PMODULES_ROOT}/${CONFIG_DIR}/Pmodules.conf" || \
-	    install -m 0644 "${SRC_DIR}/Pmodules.conf"	"${PMODULES_ROOT}/${CONFIG_DIR}"
-	
-	install -m 0644 "${SRC_DIR}/bash"		"${PMODULES_HOME}/init"
-	install -m 0644 "${SRC_DIR}/bash_completion"	"${PMODULES_HOME}/init"
-	install -m 0644 "${SRC_DIR}/csh"		"${PMODULES_HOME}/init"
-	install -m 0644 "${SRC_DIR}/zsh"		"${PMODULES_HOME}/init"
-
-	install -m 0644 "${SRC_DIR}/libpbuild.bash"	"${PMODULES_HOME}/lib"
-	install -m 0644 "${SRC_DIR}/libpbuild_dyn.bash"	"${PMODULES_HOME}/lib"
-	install -m 0644 "${SRC_DIR}/libstd.bash"	"${PMODULES_HOME}/lib"
-	install -m 0755 -d				"${PMODULES_HOME}/lib/Pmodules"
-	install -m 0644 "${SRC_DIR}/libmodules.tcl"	"${PMODULES_HOME}/lib/Pmodules"
+	install -m 0644 "${SRC_DIR}/libpbuild.bash"	"${PREFIX}/lib"
+	install -m 0644 "${SRC_DIR}/libstd.bash"	"${PREFIX}/lib"
+	install -m 0755 -d				"${PREFIX}/lib/Pmodules"
+	install -m 0644 "${SRC_DIR}/libmodules.tcl"	"${PREFIX}/lib/Pmodules"

 	{
-		PATH="${PMODULES_HOME}/${UTILBIN_DIR}:${PATH}"
-		cd "${PMODULES_HOME}/lib/Pmodules"
+		PATH="${PREFIX}/${UTILBIN_DIR}:${PATH}"
+		cd "${PREFIX}/lib/Pmodules"
 		"${BOOTSTRAP_DIR}/mkindex.tcl"
 	}

-	install -m 0755 -d "${PMODULES_ROOT}/Tools/modulefiles/Pmodules"
-	install -m 0644 "${SRC_DIR}/modulefile" "${PMODULES_ROOT}/Tools/modulefiles/Pmodules/${PMODULES_VERSION}"
-	mkdir -p "${PMODULES_ROOT}/Libraries/modulefiles"
-	
+	install -m 0644 \
+		"${SRC_DIR}/modulefile" \
+		"${INSTALL_ROOT}/Tools/modulefiles/Pmodules/${VERSION}"
+
 	echo "Done..."
 }

 #=============================================================================
 #
-
-declare -a build_opts=()
-build_opts+=( '--bootstrap' )
-
 declare subcmd=''
 declare -a subcmd_args=()

@@ -552,6 +523,7 @@ while (( $# > 0 )); do
 			shift 1
 			subcmd_args=( "$@" )
 			shift $#
+			break
 			;;
 		* )
 			std::die 1 "Invalid sub-command '$1'.\n\nUse 'build --help' to get help..."
@@ -562,5 +534,10 @@ done

 [[ -n "${subcmd}" ]] || std::die 1 "Missing sub-command.\n\nUse 'build --help' to get help..."

-pmodules::${subcmd} "${subcmd_args[@]}"
+build::${subcmd} "${subcmd_args[@]}"

+# Local Variables:
+# mode: sh
+# sh-basic-offset: 8
+# tab-width: 8
+# End:
@@ -0,0 +1,9 @@
+DefaultGroups: Tools:Programming
+DefaultReleaseStages: stable
+ReleaseStages: unstable:stable:deprecated
+TmpDir: @PMODULES_TMPDIR@
+DistfilesDir: @PMODULES_DISTFILESDIR@
+
+Overlays:
+  base:
+    install_root: @INSTALL_ROOT@
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-: ${PMODULES_ROOT:=@PMODULES_ROOT@}
-: ${PMODULES_DISTFILESDIR:=@PMODULES_DISTFILESDIR@}
-: ${PMODULES_TMPDIR:=@PMODULES_TMPDIR@}
-export     PMODULES_ROOT
-export     PMODULES_DISTFILESDIR
-export     PMODULES_TMPDIR
-
-declare -x PMODULES_CONFIG_DIR='config'
-declare -x PMODULES_MODULEFILES_DIR='modulefiles'
-
-declare -x PMODULES_HOME="${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}"
-
-declare -x DefaultGroups='Tools Programming'
-declare    ReleaseStages=':unstable:stable:deprecated:'
-declare    DefaultReleaseStages='stable'
-
@@ -0,0 +1,276 @@
+= Overlays
+:TOC:
+:sectnums:
+
+Please note: This document is work in progress!
+
+== What are Overlays and for what can they be used?
+
+== Overlay configuration
+
+=== System wide
+
+==== Example
+.A system wide configuration file `/opt/psi/config/Pmodules.yaml`
+====
+....
+DefaultGroups: Tools:Programming
+DefaultReleaseStages: stable
+ReleaseStages: unstable:stable:deprecated
+TmpDir: /opt/psi/var/tmp/${USER}
+DistfilesDir: /opt/psi/var/distfiles
+
+Overlays:
+  base:
+    install_root: /opt/psi
+    modulefiles_root: /opt/psi
+  devel:
+    install_root: /opt/psi
+    modulefiles_root: ${HOME}/modulefiles
+....
+====
+==== YAML Format
+.Format
+====
+....
+Overlays:
+  <name>:
+    install_root: <installation-root>
+    modulefiles_root: <modulefiles-root>
+    type: <type of overlay>
+  ...
+....
+====
+`<name>`:: Name of overlay. Note: whitespace in the name is not supported.
+`<name>.install_root`:: The root of the software installation. This key is mandatory.
+`<name>.modulefiles_root`:: The root of the modulefile hierarchy. This key is optional and defaults to `<name>.install_root>
+`<name>.type`:: The type of the overlay, see below. This key is optional and the default value is `n`.
+
+==== Overlay types
+`n`:: Normal overlay.
+`h`:: Hiding overlay.
+`r`:: Replacing overlay.
+
+=== User defined overlays
+
+Each user can define his own overlays in `$HOME/.Pmodules/Pmodules.yaml`. 
+
+== Working with overlays
+
+== Building modules
+
+The old format of the variants file is simple but very limited and almost impossible to extend for new features. To overcome the limitations a new format using YAML for variants files has been introduced. For the time being both format are supported. But it is highly recommended to use the YAML format for new modules and to migrate existing variants files in the old format to the new.
+
+=== With a YAML variants file
+
+Information is in the YAML configuration file:
+
+==== General structure
+
+name:: The name of the Pmodule without version. Example: `hdf5`
+group:: group the module is in. Example: `MPI`
+overlay:: (optional) overlay, defaults to `base` if not specified
+relstage:: (optional) default release stage. If not defined,
+ it defaults to `unstable`,
+url:: (optional) download URL, Must be either define here or per
+ version. The environment variables `$P`, `$V`, `$V_PKG` etc. can be used.  The downloaded file is stored with the file name `$P-${V_PKG}.ext`. Whereby `ext` is derived from the URL.
+addon_sources:: (optional) array of sources for add-ons. Example: `git-lfs`
+use:: (optional) use flags.
+systems:: (optional) array of supported systems, defaults to any. Example: `[rhel6 rhel7]`.
+compilers:: (optional) array pf supported compilers, defaults to any. Example: `[gcc intel]`.
+compile-in-src:: (optional) compile in source tree, allowed vaules are `yes` and `no`, the default is `no`.
+configure-with:: (optional) If a software supports CMake and autotools, this specifies the tool to use. Allowed values are `autotools`, `cmake`, `auto`, `none`. The default is `auto`.
+versions:: array of `version` objects
+
+==== Objects of type `addon_source`
+
+name:: unique name
+url:: download URL.
+shasum:: (optional) SHA256 sum.
+
+==== Objects of type `version`
+
+dependencies:: other run-time dependencies, if any
+build_with:: dependencies required for building, if any
+overlay:: (optional) override the default. Example: `devel`.
+relstage:: (optional) override the default. Example: `unstable`.
+addon_sources:: (optional) array of sources for add-ons.
+systems:: (optional) override the default
+compilers:: (optional) override the default
+compile-in-src:: (optional) override the default
+configure-with:: (optional) override the default
+variants:: array of `variant` objects
+
+==== Object of type `variant`
+with:: hierarchical dependencies, `with` must be specified only 
+for hierarchical groups.
+dependencies:: other run-time dependencies, if any
+build_requires:: dependencies required for building, if any
+addon_sources:: (optional) array of sources for add-ons.
+use:: (optional) use flags
+overlay:: (optional) override the default. Example: `devel`.
+relstage:: (optional) override the default. Example: `unstable`.
+systems:: (optional) override the default
+compilers:: (optional) override the default
+
+==== Example of a configuration files in YAML format
+
+.YAML configuration file for serial HDF5
+====
+....
+name: hdf5
+group: MPI
+overlay: base
+relstage: stable
+url: https://support.hdfgroup.org/ftp/HDF5/releases/$P-${V_MAJOR}.${V_MINOR}/$P-${V_PKG}/src/$P-${V_PKG}.tar.gz
+systems: [rhel6,rhel7,rhel8]
+compilers: [gcc,intel,pgi]
+compile_in_sourcetree: no
+configure_with: auto
+
+versions:
+  1.12.2:
+    shasum: 3016ea56a175d2ca7f2568c8016420f7a2aad8f95e214fe7fa5485f4b80fbe51
+    variants:
+      - group_deps: 
+          compiler: 
+            gcc: [5.5.0,6.5.0,7.5.0,10.2.0,10.3.0]
+            intel: ....
+          mpi:
+            openmpi: [...]
+          #hdf5:
+        runtime_deps: 
+          cuda:10.0
+          ...
+        build_deps:
+          name:version
+
+
+
+      - with:
+        - gcc: [8.5.0,9.5.0,11.3.0,12.1.0]
+        relstage: unstable
+        overlay: devel                 
+....
+====
+
+.YAML configuration file for HDF5 (serial and parallel)
+====
+....
+name: hdf5
+overlay: base
+relstage: stable
+url: https://support.hdfgroup.org/ftp/HDF5/releases/$P-${V_MAJOR}.${V_MINOR}/$P-${V_PKG}/src/$P-${V_PKG}.tar.gz
+systems: [rhel6 rhel7 rhel8]
+compilers: [gcc intel pgi]
+compile_in_sourcetree: no
+configure_with: auto
+
+versions:
+  1.12.2:
+    shasum: 3016ea56a175d2ca7f2568c8016420f7a2aad8f95e214fe7fa5485f4b80fbe51
+    variants:
+      - with:
+          - gcc [5.5.0 6.5.0 7.5.0 10.2.0 10.3.0] 
+        group: Compiler
+      - with:
+          - gcc [8.5.0,9.5.0,11.3.0,12.1.0]
+          - openmpi [4.0.5-2]
+        group: MPI
+        relstage: unstable
+        overlay: devel                 
+....
+====
+
+.YAML configuration file for Git with git-lfs
+====
+....
+name: git
+defaults:
+  group: Tools
+  overlay: base
+  relstage: stable
+  url: https://mirrors.edge.kernel.org/pub/software/scm/$P/$P-${V_PKG}.tar.xz
+  systems: [rhel6 rhel7 rhel8]
+  compilers: [gcc]
+  compile_in_sourcetree: yes
+  configure_with: auto
+  script: build
+
+addons:
+  git-lfs/3.2.0:
+    - url: https://github.com/git-lfs/git-lfs/archive/refs/tags/v3.2.0.tar.gz
+      shasum: f8e6bbe043b97db8a5c16da7289e149a3fed9f4d4f11cffcc6e517c7870cd9e5
+      build_requires: [go/1.19] 
+      build_script: build-git-lfs   
+
+versions:
+  2.37.2:
+    shasum: 4c428908e3a2dca4174df6ef49acc995a4fdb1b45205a2c79794487a33bc06e5
+    variants:
+      - dependencies: TclTk/8.6.9
+        build_requires: [perl/5.30.0 asciidoc/8.6.9-1 xmlto/0.0.28 gettext/0.19.8]
+        relstage: unstable
+        overlay: devel
+        addons:
+          git-lfs: 3.2.0
+      
+....
+====
+
+==== Format specification
+.YAML format
+....
+name: <Pmodule-name-without-version>
+source_url: "https://..."
+overlay: <opt-default-overlay>
+group: <default-group>
+relstage: <opt-default-release-stage>
+systems: [opt-array-of-supported]
+compilers: [opt-array-of-supported-compilers]
+compile-in-src: yes|no
+configure-with: cmake|autotools|auto|none
+
+versions:
+  - <version1>:
+      overlay: <overlay>
+      group: <group>
+      relstage: <release-stage>
+      systems: [supported-systems]
+      sources:
+        - url: <url>
+          shasum: <shasum>
+      compilers: <default-list-of-supported-compilers>
+      compile-in-src: yes|no
+      configure-with: cmake|autotools|auto|none
+      variants:
+        - with:
+          - gcc: [5.5.0,6.5.0,7.5.0,10.2.0,10.3.0]
+          dependencies: [array-of-runtime-deps]
+          build_requires: [array-of-build-deps]
+          relstage: <release-stage>
+          use: [array-of-use-flags]
+          overlay: <overlay>
+        ...
+....
+==== Defaults
+Default values can be overriden per version/variant.
+
+`overlay`:: The default overlay the module will be installed in. This value can be overriden for dedicated versions/variants.
+`systems`:: The default for supported systems.
+
+==== Versions and Variants
+
+`<name>/<version>`:: An array with variants for this version.
+
+`<name>/<version>.[i].with`:: Hierarchical dependencies for variant `i`.
+
+`<name>/<version>.[i].dependencies`:: Build/run-time dependencies for variant `i`.
+
+`<name>/<version>.[i].relstage`:: Relase stage of variant `i`.
+
+`<name>/<version>.[i].overlay`:: Overlay of variant `i`.
+
+`<name>/<version>.[i].systems`:: Supported systems.
+
+=== Legacy format
@@ -0,0 +1,42 @@
+#!/bin/bash
+#
+# https://www.gnu.org/software/bash/
+#
+P=bash
+V=${BASH5_VERSION:-5.1.16}
+FNAME="$P-$V.tar.gz"
+DOWNLOAD_URL="https://ftp.gnu.org/gnu/$P/${FNAME}"
+
+source "$(dirname "$0")/librecipes.bash"
+
+#---
+# configure
+mkdir -p "${BUILD_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+loadablesdir="${PREFIX}/${UTILBIN_DIR}/builtins" \
+"${SRC_DIR}/configure" \
+	--prefix="${PREFIX}" \
+	--bindir="${PREFIX}/${UTILBIN_DIR}" \
+        || exit ${PB_ERR_CONFIGURE}
+
+#---
+# compile
+make -j ${NJOBS} || exit ${PB_ERR_MAKE}
+make -C examples/loadables -j ${NJOBS} || exit ${PB_ERR_MAKE}
+
+#---
+# install
+make install || exit ${PB_ERR_INSTALL}
+
+#---
+# post-install
+rm -rf "${PREFIX}/include/bash"
+rm -rf "${PREFIX}/share/locale"
+rm -rf "${PREFIX}/share/doc"
+rm -rf "${PREFIX}/share/info"
+rm -rf "${PREFIX}/share/man/man1/bash"*
+
+#---
+# Local Variables:
+# mode: shell-script-mode
+# sh-basic-offset: 8
+# End:
@@ -0,0 +1,60 @@
+#!/bin/bash
+#
+# https://www.tcl.tk
+#
+P=tcl
+V=${TCL_VERSION:-8.6.12}
+FNAME="$P$V-src.tar.gz"
+DOWNLOAD_URL="https://prdownloads.sourceforge.net/tcl/${FNAME}"
+
+source "$(dirname "$0")/librecipes.bash"
+
+#---
+# download
+test -r "${SRC_FILE}" || curl -L --output "$_" "${DOWNLOAD_URL}" || exit ${PB_ERR_DOWNLOAD}
+
+#---
+# unpack
+mkdir -p "${SRC_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+tar --directory "${SRC_DIR}" --strip-components 1 -xv -f "${SRC_FILE}" || exit ${PB_ERR_UNTAR}
+
+#---
+# configure
+mkdir -p "${BUILD_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+case $(uname -s) in
+Linux )
+	srcdir="${SRC_DIR}/unix"
+	;;
+Darwin )
+	srcdir="${SRC_DIR}/macosx"
+	;;
+* )
+	echo "Oops: unsupported OS!" 1>&2
+	exit ${PB_ERR_SYSTEM}
+	;;
+esac
+"${srcdir}"/configure \
+	--prefix="${PREFIX}" \
+	--bindir="${PREFIX}/${UTILBIN_DIR}" \
+	--mandir="${PREFIX}/share/man" \
+	--enable-shared=no \
+        || exit ${PB_ERR_CONFIGURE}
+
+#---
+# compile & install
+make -j ${NJOBS} || exit ${PB_ERR_MAKE}
+make install || exit ${PB_ERR_INSTALL}
+
+#---
+# post-install
+{ cd "${PREFIX}/${UTILBIN_DIR}" && rm -f tclsh && ln -fs tclsh${V%.*} tclsh; };
+
+rm -rf "${PREFIX}/share/man/man1/tclsh.1"
+rm -rf "${PREFIX}/share/man/man3"
+rm -rf "${PREFIX}/share/man/mann"
+
+#---
+# Local Variables:
+# mode: shell-script-mode
+# sh-basic-offset: 8
+# End:
@@ -0,0 +1,48 @@
+#!/bin/bash
+#
+# https://core.tcl-lang.org
+#
+P=tcllib
+V=${TCLLIB_VERSION:-1.21}
+FNAME="$P-$V.tar.gz"
+DOWNLOAD_URL="https://core.tcl-lang.org/tcllib/uv/${FNAME}" 
+
+source "$(dirname "$0")/librecipes.bash"
+
+#---
+# download
+test -r "${SRC_FILE}" || curl -L --output "$_" "${DOWNLOAD_URL}" || exit ${PB_ERR_DOWNLOAD}
+
+#---
+# unpack
+mkdir -p "${SRC_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+tar --directory "${SRC_DIR}" --strip-components 1 -xv -f "${SRC_FILE}" || exit ${PB_ERR_UNTAR}
+# configure
+mkdir -p "${BUILD_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+"${SRC_DIR}"/configure \
+	--prefix="${PREFIX}" \
+	--mandir="${PREFIX}/share/man" \
+        || exit ${PB_ERR_CONFIGURE}
+
+#---
+# compile & install
+make -j ${NJOBS} || exit ${PB_ERR_MAKE}
+make install || exit ${PB_ERR_INSTALL}
+
+#---
+# post-install
+rm -rf "${PREFIX}/share/man/mann"
+rm -f  "${PREFIX}/bin/dtplite"
+rm -f  "${PREFIX}/bin/mkdoc"
+rm -f  "${PREFIX}/bin/nns"
+rm -f  "${PREFIX}/bin/nnsd"
+rm -f  "${PREFIX}/bin/nnslog"
+rm -f  "${PREFIX}/bin/page"
+rm -f  "${PREFIX}/bin/pt"
+rm -f  "${PREFIX}/bin/tcldocstrip"
+
+#---
+# Local Variables:
+# mode: shell-script-mode
+# sh-basic-offset: 8
+# End:
@@ -0,0 +1,59 @@
+#!/bin/bash
+#
+# https://core.tcl-lang.org
+#
+P=modules
+V=${MODULES_VERSION:-3.2.10.1}
+FNAME="$P-$V.tar.gz"
+DOWNLOAD_URL="https://amas.web.psi.ch/Downloads/$P/$P-$V.tar.bz2"
+
+source "$(dirname "$0")/librecipes.bash"
+
+#---
+# configure
+mkdir -p "${BUILD_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+case $(uname -s) in
+	Linux )
+		declare -x LIBS="-lz -lpthread"
+		;;
+	Darwin )
+		declare -x LIBS="-lz -framework CoreFoundation"
+		;;
+	* )
+		echo "Oops: unsupported OS!" 1>&2
+		exit ${PB_ERR_SYSTEM}
+		;;
+esac
+CPPFLAGS="-DUSE_INTERP_ERRORLINE" \
+"${SRC_DIR}"/configure \
+	--prefix="${PREFIX}" \
+	--exec-prefix="${PREFIX}" \
+	--with-module-path="${PREFIX%%/Tools*}/Tools/${PMODULES_MODULEFILES_DIR}" \
+	--with-tcl="${PREFIX}/lib" \
+	--without-x \
+	--disable-versioning \
+        || exit ${PB_ERR_CONFIGURE}
+
+#---
+# compile & install
+make -j ${NJOBS} || exit ${PB_ERR_MAKE}
+make install || exit ${PB_ERR_INSTALL}
+
+#---
+# post-install
+mkdir -p "${PREFIX}/share/man/man1"
+mkdir -p "${PREFIX}/share/man/man4"
+mv -v    "${PREFIX}/Modules/share/man/man1/module.1" "${PREFIX}/share/man/man1"
+mv -v    "${PREFIX}/Modules/share/man/man4/modulefile.4" "${PREFIX}/share/man/man4"
+mkdir -p "${PREFIX}/libexec"
+cp -v    "${BUILD_DIR}/modulecmd" "${PREFIX}/libexec/modulecmd.bin" || exit 1
+
+rm -rf  "${PREFIX}/Modules"
+rm -f	"${PREIX}"/init/{ksh,perl.pm,python.py,ruby.rb,cmake,.modulespath}
+
+#---
+# Local Variables:
+# mode: sh
+# sh-basic-offset: 8
+# tab-width: 8
+# End:
@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+#
+# https://frodo.looijaard.name/project/getopt
+#
+P=getopt
+V=${GETOPT_VERSION:-1.1.6}
+FNAME="$P-$V.tar.gz"
+DOWNLOAD_URL="http://frodo.looijaard.name/system/files/software/$P/$P-$V.tar.gz"
+
+#---
+# build on macOS only
+[[ $(uname -s) == 'Darwin' ]] || exit 0
+
+#---
+source "$(dirname "$0")/librecipes.bash"
+
+#---
+# configure
+# nothing to configure but we need gettext from Macports
+if [[ ! -d '/opt/local/bin' ]] || [[ ! -x '/opt/local/bin/msgfmt' ]]; then
+	echo "gettext port from Macports is required to build 'getopt'!" 1>&2
+	exit 1
+fi
+
+#---
+# compile
+PATH+=':/opt/local/bin'
+declare -x C_INCLUDE_PATH="${PREFIX}/include:/opt/local/include"
+declare -x LDFLAGS="/opt/local/lib/libintl.a /opt/local/lib/libiconv.a -framework CoreFoundation"
+declare -x LIBRARY_PATH="${PREFIX}/lib"
+
+make -e all || exit 1
+
+#---
+# install
+declare -x DESTDIR="${PREFIX}"
+declare -x prefix='' 
+#PATH="${PREFIX}/${UTILBIN_DIR}:${PATH}"
+make -e install
+
+#---
+# post-install
+mv "${PREFIX}/bin/getopt" "${PREFIX}/${UTILBIN_DIR}"
+rm -rf "${PREFIX}/man"
+rm -rf "${PREFIX}/share/locale"
+
+#---
+# Local Variables:
+# mode: sh
+# sh-basic-offset: 8
+# tab-width: 8
+# End:
@@ -0,0 +1,43 @@
+#!/bin/bash
+#
+# https://www.gnu.org/software/findutils/
+#
+P=findutils
+V=${FINDUTILS_VERSION:-4.9.0}
+FNAME="$P-$V.tar.xz"
+DOWNLOAD_URL="https://ftp.gnu.org/gnu/$P/${FNAME}"
+
+#---
+# build on macOS only
+[[ $(uname -s) == 'Darwin' ]] || exit 0
+
+#---
+source "$(dirname "$0")/librecipes.bash"
+
+#---
+# configure
+mkdir -p "${BUILD_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+loadablesdir="${PREFIX}/${UTILBIN_DIR}/builtins" \
+"${SRC_DIR}/configure" \
+	--prefix="${PREFIX}" \
+	--bindir="${PREFIX}/${UTILBIN_DIR}" \
+        || exit ${PB_ERR_CONFIGURE}
+
+#---
+# compile & install
+make -j ${NJOBS} || exit ${PB_ERR_MAKE}
+make install || exit ${PB_ERR_INSTALL}
+
+#---
+# post-install
+rm -vf "${PREFIX}/share/man/man5/locatedb.5"
+rm -vf "${PREFIX}/share/man/man1/updatedb.1"
+rm -vf "${PREFIX}/share/man/man1/xargs.1"
+rm -vf "${PREFIX}/share/man/man1/locate.1"
+rm -vf "${PREFIX}/share/man/man1/find.1"
+
+#---
+# Local Variables:
+# mode: shell-script-mode
+# sh-basic-offset: 8
+# End:
@@ -0,0 +1,91 @@
+#!/bin/bash
+
+set -x
+set -o errexit
+set -o pipefail
+shopt -s nullglob
+
+if (( $# == 0 )); then
+	echo "Usage: $0 <dest-dir>" 1>&2 
+	exit 1
+fi
+
+PREFIX="$1"
+if [[ ! -d ${PREFIX} ]]; then
+	echo "Destinstion directory '${PREFIX}' does not exist! Aborting..." 1>&2
+	exit 2
+fi
+TMP_DIR="${PMODULES_TMPDIR:-/var/tmp/${USER}}"
+DOWNLOADS_DIR="${PMODULES_DISTFILESDIR:-${TMP_DIR}/Downloads}"
+SRC_DIR="${TMP_DIR}/$P-$V/src"
+BUILD_DIR="${TMP_DIR}/$P-$V/build"
+SRC_FILE="${DOWNLOADS_DIR}/${FNAME}"
+
+
+declare -ix PB_ERR_ARG=1
+declare -ix PB_ERR_SETUP=2
+declare -ix PB_ERR_SYSTEM=3
+declare -ix PB_ERR_DOWNLOAD=4
+declare -ix PB_ERR_UNTAR=5
+declare -ix PB_ERR_CONFIGURE=6
+declare -ix PB_ERR_MAKE=7
+declare -ix PB_ERR_PRE_INSTALL=8
+declare -ix PB_ERR_INSTALL=9
+declare -ix PB_ERR_POST_INSTALL=10
+declare -ix PB_ERR=255
+declare -ix NJOBS=4
+
+pb_exit() {
+        local -i ec=$?
+        if [[ -n "${BASH_VERSION}" ]]; then
+                local -i n=${#BASH_SOURCE[@]}
+                local -r recipe_name="${BASH_SOURCE[n]}"
+        else
+                local -r recipe_name="${ZSH_ARGZERO}"
+        fi
+        echo -n "${recipe_name}: "
+        if (( ec == 0 )); then
+                echo "done!"
+        elif (( ec == PB_ERR_ARG )); then
+                echo "argument error!"
+        elif (( ec == PB_ERR_SETUP )); then
+                echo "error in setting everything up!"
+        elif (( ec == PB_ERR_SYSTEM )); then
+                echo "unexpected system error!"
+        elif (( ec == PB_ERR_DOWNLOAD )); then
+                echo "error in downloading the source file!"
+        elif (( ec == PB_ERR_UNTAR )); then
+                echo "error in un-taring the source file!"
+        elif (( ec == PB_ERR_CONFIGURE )); then
+                echo "error in configuring the software!"
+        elif (( ec == PB_ERR_MAKE )); then
+                echo "error in compiling the software!"
+        elif (( ec == PB_ERR_PRE_INSTALL )); then
+                echo "error in pre-installing the software!"
+        elif (( ec == PB_ERR_INSTALL )); then
+                echo "error in installing the software!"
+        elif (( ec == PB_ERR_POST_INSTALL )); then
+                echo "error in post-installing the software!"
+        else
+                echo "oops, unknown error!!!"
+        fi
+        exit ${ec}
+}
+#export -f pb_exit > /dev/null
+trap "pb_exit" EXIT
+
+#---
+# download
+mkdir -p "${DOWNLOADS_DIR}" || exit ${PB_ERR_SYSTEM}
+test -r "${SRC_FILE}" || curl -L --output "$_" "${DOWNLOAD_URL}" || exit ${PB_ERR_DOWNLOAD}
+
+#---
+# unpack
+mkdir -p "${SRC_DIR}" && cd "$_" || exit ${PB_ERR_SYSTEM}
+tar --directory "${SRC_DIR}" --strip-components 1 -xv -f "${SRC_FILE}" || exit ${PB_ERR_UNTAR}
+
+#---
+# Local Variables:
+# mode: shell-script-mode
+# sh-basic-offset: 8
+# End: