--- a/.hgignore	Fri Nov 17 00:51:31 2017 +0100
+++ b/.hgignore	Sat Nov 25 17:47:02 2017 -0500
@@ -6,7 +6,7 @@
 \.swp$
 \.orig$
 \.rej$
-\.err$
+^tests/.*\.err$
 ^tests/easy_run.sh$
 ^build/
 ^dist/