--- a/Makefile.am Sun Jun 22 16:35:34 2014 -0700
+++ b/Makefile.am Sun Jun 22 23:48:33 2014 -0700
@@ -117,7 +117,7 @@
(hg --cwd $(srcdir) id -i --debug) 2>/dev/null >$@.new \
$(AM_V_at)if test -f $@.new; then \
- if ! diff $@ $@.new > /dev/null; then \
+ if ! test -f "$@" || ! diff "$@" "$@".new > /dev/null ; then \