configury: fix git describe with VPATH

config/opal_get_version.m4

@@ -12,6 +12,8 @@ dnl Copyright (c) 2004-2005 The Regents of the University of California.
 dnl                         All rights reserved.
 dnl Copyright (c) 2008-2014 Cisco Systems, Inc.  All rights reserved.
 dnl Copyright (c) 2014      Intel, Inc. All rights reserved.
+dnl Copyright (c) 2014      Research Organization for Information Science
+dnl                         and Technology (RIST). All rights reserved.
 dnl $COPYRIGHT$
 dnl
 dnl Additional copyrights may follow
@@ -79,7 +81,15 @@ m4_define([OPAL_GET_VERSION],[
             # If we're in a git repo and we found the git command, use
             # git describe to get the repo rev
             if test -d "$srcdir/.git" && test $git_happy -eq 1; then
-                $2_REPO_REV=`git describe --tags --always`
+                if test "$srcdir" != "`pwd`"; then
+                    git_save_dir=`pwd`
+                    cd $srcdir
+                    $2_REPO_REV=`git describe --tags --always`
+                    cd $git_save_dir
+                    unset git_save_dir
+                else
+                    $2_REPO_REV=`git describe --tags --always`
+                fi
             else
                 $2_REPO_REV="date`date '+%Y-%m-%d'`"
             fi