diff -r 1aedbf3ef3d1 -r 07e181ed82ef tests/test-filebranch.t
--- a/tests/test-filebranch.t	Sun Dec 09 18:35:35 2018 -0500
+++ b/tests/test-filebranch.t	Sun Dec 09 21:23:34 2018 -0500
@@ -6,7 +6,7 @@
   > import sys, os
   > print("merging for", os.path.basename(sys.argv[1]))
   > EOF
-  $ HGMERGE="$PYTHON ../merge"; export HGMERGE
+  $ HGMERGE="\"$PYTHON\" ../merge"; export HGMERGE
 
 Creating base: