Re: t2400 on freebsd12

[Junio C Hamano <gitster@pobox.com>]

Eric Sunshine <sunshine@sunshineco.com> writes:

> I haven't been following this thread closely, but I wonder if the
> `grep` introduced by patch [3/8] of the cited patch series is
> problematic:
>
>     grep -E "fatal:( options)? .* cannot be used together" actual
>
> since BSD lineage regexp (including macOS) historically did not
> support the "?" repetition operator. Perhaps an easy fix would be to
> simplify this to:
>
>     grep "cannot be used together" actual

We do not seem to get the same breakage on macOS CI runs (otherwise
this would have been caught much earlier).  We do have many "grep
-E" invocations to ask for ERE but not many of them uses zero-or-one
'?'  in our test suite.  But I would be somewhat surprised if
test_dir_is_empty is broken on FreeBSD and nobody has noticed it for
this long.

I got an impression from the discussion so far that this breakage is
flaky and not always reproducible.  I wonder if "stress" thing helps
the chance to reproduce for those with FreeBSD boxes?

   $ cd t && sh ./t2400-* --stress

Thanks.