diff --git a/lib/Tools/getenv b/lib/Tools/getenv
--- a/lib/Tools/getenv
+++ b/lib/Tools/getenv
@@ -1,81 +1,85 @@
 #!/usr/bin/env bash
 #
 # Author: Markus Wenzel, TU Muenchen
 #
 # DESCRIPTION: get values from Isabelle settings environment
 
 
 ## diagnostics
 
 PRG="$(basename "$0")"
 
 function usage()
 {
   echo
   echo "Usage: isabelle $PRG [OPTIONS] [VARNAMES ...]"
   echo
   echo "  Options are:"
   echo "    -a           display complete environment"
   echo "    -b           print values only (doesn't work for -a)"
   echo "    -d FILE      dump complete environment to file (NUL terminated entries)"
   echo
   echo "  Get value of VARNAMES from the Isabelle settings."
   echo
   exit 1
 }
 
 
 ## process command line
 
 # options
 
 ALL=""
 BASE=""
 DUMP=""
 
 while getopts "abd:" OPT
 do
   case "$OPT" in
     a)
       ALL=true
       ;;
     b)
       BASE=true
       ;;
     d)
       DUMP="$OPTARG"
       ;;
     \?)
       usage
       ;;
   esac
 done
 
 shift $(($OPTIND - 1))
 
 
 # args
 
 [ -z "$ALL" -a -z "$DUMP" -a "$#" -eq 0 ] && usage
 [ -n "$ALL" -a "$#" -ne 0 ] && usage
 
 
 ## main
 
 if [ -n "$ALL" ]; then
   env
 else
   for VAR in "$@"
   do
     if [ -n "$BASE" ]; then
       eval "echo \$$VAR"
     else
       eval "echo $VAR=\$$VAR"
     fi
   done
 fi
 
 if [ -n "$DUMP" ]; then
   export PATH_JVM="$(platform_path "$PATH")"
-  "$ISABELLE_PRINTENV" -0 > "$DUMP"
+  if [ -e "$ISABELLE_PRINTENV" ]; then
+    "$ISABELLE_PRINTENV" -0 > "$DUMP"
+  else
+    exit 2
+  fi
 fi