--- a/tests/test-check-help.t	Thu Jun 15 14:22:39 2017 -0400
+++ b/tests/test-check-help.t	Tue Jun 20 09:45:02 2017 -0400
@@ -24,5 +24,5 @@
 (use "xargs -n1 -t" to see which help commands are executed)
 
   $ hg files 'glob:{hgdemandimport,hgext,mercurial}/**/*.py' | sed 's|\\|/|g' \
-  > | xargs python "$TESTTMP/scanhelptopics.py" \
+  > | xargs $PYTHON "$TESTTMP/scanhelptopics.py" \
   > | xargs -n1 hg help > /dev/null