--- a/.hgignore	Fri Mar 25 11:33:12 2022 -0400
+++ b/.hgignore	Sun Mar 13 15:48:18 2022 +0100
@@ -22,6 +22,8 @@
 tests/artifacts/cache/big-file-churn.hg
 tests/.coverage*
 tests/.testtimes*
+# the file is written in the CWD when run-tests is run.
+.testtimes
 tests/.hypothesis
 tests/hypothesis-generated
 tests/annotated