--- a/tests/test-merge1.t	Sun Dec 09 18:35:35 2018 -0500
+++ b/tests/test-merge1.t	Sun Dec 09 21:23:34 2018 -0500
@@ -11,7 +11,7 @@
   > 
   > print("merging for", os.path.basename(sys.argv[1]))
   > EOF
-  $ HGMERGE="$PYTHON ../merge"; export HGMERGE
+  $ HGMERGE="\"$PYTHON\" ../merge"; export HGMERGE
 
   $ hg init t
   $ cd t