Re: [RFC/PATCH 0/5] Fix fetch regression with transport helpers

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Duy,

On Wed, 5 Jun 2019, Duy Nguyen wrote:

> On Wed, Jun 5, 2019 at 6:27 PM Jeff King <peff@peff.net> wrote:
> >
> > On Wed, Jun 05, 2019 at 10:12:12AM +0200, Johannes Schindelin wrote:
> >
> > > This fails on macOS, in t5601, both in our osx-clang and osx-gcc jobs, as
> > > well as in the StaticAnalysis job. For details, see
> > > https://dev.azure.com/gitgitgadget/git/_build/results?buildId=10206
> >
> > Hmm. I'm having a hard time seeing why (and I can't seem to reproduce it
> > locally on a case-insensitive HFS+ filesystem under Linux).
> >
> > In particular, if the problem is here:
> >
> > > expecting success:
> > >       grep X icasefs/warning &&
> > >       grep x icasefs/warning &&
> > >       test_i18ngrep "the following paths have collided" icasefs/warning
> > >
> > > ++ grep X icasefs/warning
> > > error: last command exited with $?=1
> > > not ok 99 - colliding file detection
> >
> > then that implies it has to do with the checkout phase, which Felipe's
> > patch doesn't touch. Later in the log we see the actual file contents
> > (I'm confused as to how this gets here; it looks like debugging bits
> > that were added after the main script?):
> >
> >   2019-06-05T07:58:37.7961890Z Cloning into 'bogus'...
> >   2019-06-05T07:58:37.7962430Z done.
> >   2019-06-05T07:58:37.7963360Z warning: the following paths have collided (e.g. case-sensitive paths
> >   2019-06-05T07:58:37.7964300Z on a case-insensitive filesystem) and only one from the same
> >   2019-06-05T07:58:37.7964880Z colliding group is in the working tree:
> >   2019-06-05T07:58:37.7965290Z
> >   2019-06-05T07:58:37.7966250Z   'x'
> >
> > whereas a succeeding test expects us to mention both 'x' and 'X'.
> >
> > So we _did_ find the collision, but somehow 'X' was not reported.
> > Looking at the code, I'm not even sure how that could happen. Given that
> > this process does involve looking at stat data, it makes me wonder if
>
> It does use stat data in mark_colliding_entries() if core.checkStat is
> false. I think on MacOS it's actually true.
>
> I vaguely recall seeing just one 'x' once. I think last time I had a
> problem with truncating st_ino, but that should be fixed in e66ceca94b
> (clone: fix colliding file detection on APFS, 2018-11-20). So no idea
> how this happens again.

Good catch. I think the reason it happens again is simply that Junio
picked a base commit that is older than the commit you referenced.

Point in favor: Junio merged these here patches into `pu` and those
test failures (as well as the StaticAnalysis issues) are gone.

Thanks,
Johannes

>
> > there could be some raciness involved. But again, I'm scratching my head
> > as to how exactly, and I couldn't reproduce it under load or with some
> > carefully inserted sleep() calls.
> --
> Duy
>