diff --git a/.tools/make-tar.sh b/.tools/make-tar.sh
index 4bb0c8a3a..3d676e109 100755
--- a/.tools/make-tar.sh
+++ b/.tools/make-tar.sh
@@ -1,22 +1,26 @@
-#!/bin/sh
+#!/bin/bash
 #
 # Make tar for git repo w/ one level of sub modules.
 #
-set -e
+set -e -u
 
 die() {
   echo "$1" >&2
   exit 1
 }
 
-TOPREV="$1"
-FINALTAR="$2"
-PREFIX="$3"
+maybedie() {
+  if [ "$DEVMODE" ]; then
+    echo "Warning: $1" >&2
+  else
+    echo "Error: $1" >&2
+    exit 1
+  fi
+}
 
-if ! [ "$TOPREV" ]
-then
+usage() {
    cat <<EOF >&2
-usage: $0 <rev> [<outfile> [<prefix>]]
+usage: $0 [-v] [-s] <rev> [<outfile> [<prefix>]]
 
   <rev> may be any git revision spec. (tag, branch, or commit id).
 
@@ -24,9 +28,33 @@ usage: $0 <rev> [<outfile> [<prefix>]]
   If <outfile> is omitted, "base-<rev>.tar.gz" will be used.
   If provided, <prefix> must end with "/".  If <prefix> is omitted,
   the default is "base-<rev>/".
+
+  Options:
+
+    -v   Enable verbose prints
+    -d   Enable permissive developer mode
 EOF
    exit 1
-fi
+}
+
+export DEVMODE=
+
+while getopts "vd" OPT
+do
+    case "$OPT" in
+    v) set -x;;
+    d) DEVMODE=1;;
+    ?) echo "Unknown option"
+       usage;;
+    esac
+done
+shift $(($OPTIND - 1))
+
+TOPREV="$1"
+FINALTAR="$2"
+PREFIX="${3:-}"
+
+[ "$TOPREV" ] || usage
 
 case "$FINALTAR" in
 "")
@@ -59,16 +87,13 @@ case "$PREFIX" in
 esac
 
 # Check for both <tag> and R<tag>
-if [ "$TOPREV" = "HEAD" ]
-then
-  true
-elif ! [ `git tag -l $TOPREV` ]
+if ! [ `git tag -l $TOPREV` ]
 then
   if [ `git tag -l R$TOPREV` ]
   then
     TOPREV="R$TOPREV"
   else
-    die "No tags exist '$TOPREV' or 'R$TOPREV'"
+    maybedie "No tags exist '$TOPREV' or 'R$TOPREV'"
   fi
 fi
 
@@ -94,7 +119,12 @@ git ls-tree -r $TOPREV | \
 while read HASH MODDIR
 do
     echo "Visiting $HASH $MODDIR"
-    git -C $MODDIR archive --prefix=${PREFIX}${MODDIR}/ $HASH | tar -C "$TDIR"/tar -x
+    if [ -e $MODDIR/.git ]
+    then
+        git -C $MODDIR archive --prefix=${PREFIX}${MODDIR}/ $HASH | tar -C "$TDIR"/tar -x
+    else
+        maybedie "  Submodule not checked out."
+    fi
 done
 
 # make a list of files copied and filter out undesirables
@@ -134,5 +164,5 @@ tar -t $TAROPT -f "$FINALTAR" > "$TDIR"/list.3
 # make sure we haven't picked up anything extra
 if ! diff -u "$TDIR"/list.2 "$TDIR"/list.3
 then
-    echo "Oops! Tarfile diff against plan shown above"
+    die "Oops! Tarfile diff against plan shown above"
 fi