Some tests will start failing with grep 3.8
As noticed by @Jade, grep 3.8 has added a new warning about "stray \" when normal characters are unnecessarily escaped. https://github.com/koalaman/shellcheck/issues/2573 has a good breakdown.
This causes (or will cause) some tests to fail.
=====> T12504(normal) 1 of 1 [0, 0, 0]
cd "/tmp/ghctest-u89j_ci9/test spaces/testsuite/tests/hsc2hs/T12504.run" && $MAKE -s --no-print-directory T12504 <
Actual stderr output differs from expected:
diff -uw "/dev/null" "/tmp/ghctest-u89j_ci9/test spaces/testsuite/tests/hsc2hs/T12504.run/T12504.run.stderr.normalised"<
--- /dev/null 2023-05-06 18:59:00.573333256 +0200
+++ "/tmp/ghctest-u89j_ci9/test spaces/testsuite/tests/hsc2hs/T12504.run/T12504.run.stderr.normalised" 2023-05-06 21:35:53.516489200 +0200
@@ -0,0 +1,2 @@
+grep: warning: stray / before "
+grep: warning: stray / before "
*** unexpected failure for T12504(normal)
I think we can proactively fix this by removing the stray '\' before CI ever picks up the new version of grep.
There may also be a grep flag that will disable the warning, but I haven't looked yet.