--- a/tests/test-check-rust-format.t	Fri Feb 11 23:43:17 2022 +0100
+++ b/tests/test-check-rust-format.t	Mon Feb 14 19:03:22 2022 +0100
@@ -3,6 +3,8 @@
   $ . "$TESTDIR/helpers-testrepo.sh"
 
   $ cd "$TESTDIR"/..
+
+Warning: Keep this in sync with hghave.py
   $ RUSTFMT=$(rustup which --toolchain nightly-2021-11-02 rustfmt)
   $ for f in `testrepohg files 'glob:**/*.rs'` ; do
   >   $RUSTFMT --check --edition=2018 --unstable-features --color=never $f