diff --git a/tests/test-merge-revert b/tests/test-merge-revert
--- a/tests/test-merge-revert
+++ b/tests/test-merge-revert
@@ -1,4 +1,5 @@
 #!/bin/sh
+# FIXME: This test may fail due to an uncritical bug in Mercurial.
 
 mkdir t
 cd t