build-system: error in cleanup

Cleanup before building fails if ${BUILD_DIR}/../.. doesn't exist.

CHANGELOG.md

@@ -13,7 +13,7 @@
   (issues #235, #243)
 * Files in `$PMODULES_TMPDIR/<module>` are now removed before
   and after building a module (except cleanup has been disbaled).
-  (issue #242)
+  (issues #242, #245)
 * Set prefix and directory/name of modulefile based on group not on
   environment variables like `{COMPILER,MPI,HDF5}_VERSION` (issue #244)
 

Pmodules/libpbuild.bash

@@ -1551,6 +1551,7 @@ _build_module() {
 	cleanup_build() {
 		[[ ${enable_cleanup_build} != 'yes' ]] && return 0
 		[[ "${BUILD_DIR}" == "${SRC_DIR}" ]] && return 0
+		[[ -d "${BUILD_DIR}/../.." ]] || return 0
 		{
 			cd "/${BUILD_DIR}/.." || std::die 42 "Internal error"
 			[[ "$(${pwd})" == "/" ]] && \
@@ -1570,6 +1571,7 @@ _build_module() {
 
 	cleanup_src() {
 		[[ ${enable_cleanup_src} != 'yes' ]] && return 0
+		[[ -d "${BUILD_DIR}/../.." ]] || return 0
     		{
 			cd "/${SRC_DIR}/.." || std::die 42 "Internal error"
 			[[ $(pwd) == / ]] && \