bug#28906: flymake test different-diagnostic-types fails

[João Távora]

Glenn Morris <rgm@gnu.org> writes:

> Package: emacs
> Version: 26.0.90
>
> Between 0fff900c18c3ae497294f26fd42b70990638d3ed and
> 0b558b4acb8326c6f26fcde47ca85777716ae831 on emacs-26 (RHEL7 with gcc 4.8.5),
> the flymake test "different-diagnostic-types" began failing with:
>
> (should (eq 'flymake-note (face-at-point)))
> -> (eq flymake-note flymake-warning)
>
> Ref also eg https://hydra.nixos.org/build/62738472

This appears to be the first test run since the Flymake rewrite that was
merged into emacs-26, so the test didn't really "begin failing", it just
didn't exist before that.

Anyway, I think there's a good chance that the culprit is gcc version
4.8.5 which probably outputs something that Flymake can't recognize as a
note. 

Is there any chance that Hydra can be upgraded to use a newer gcc, or
should I skip this test for such gcc versions? Tips on how to install
gcc 4 on debian alongside the system gcc are also welcome.

João