--- a/tests/test-blackbox.t	Tue Mar 08 20:57:40 2016 +0000
+++ b/tests/test-blackbox.t	Tue Mar 08 20:52:57 2016 +0000
@@ -157,7 +157,7 @@
   $ sed -e 's/\(.*test1.*\)/#\1/; s#\(.*commit2.*\)#os.rmdir(".hg/blackbox.log")\
   > os.rename(".hg/blackbox.log-", ".hg/blackbox.log")\
   > \1#' $TESTDIR/test-dispatch.py > ../test-dispatch.py
-  $ python ../test-dispatch.py
+  $ python $TESTDIR/blackbox-readonly-dispatch.py
   running: add foo
   result: 0
   running: commit -m commit1 -d 2000-01-01 foo