r239402 - Remove rm invocations where the file is immediately rewritten later.

[Benjamin Kramer]

On Tue, Jun 9, 2015 at 6:02 PM, Greg Bedwell <gregbedwell at gmail.com> wrote:
>>
>> Remove rm invocations where the file is immediately rewritten later.
>>
>> This may or may not help making this test less flaky on windows. There's
>> a race condition in lit somewhere.
>>
>
> I've always assumed that this is just Windows holding onto the file for too
> long, possibly exacerbated by the presence of AV software, rather than an
> issue with lit itself although I'm just wildly speculating based on previous
> experience with this sort of thing.  I'm still hitting this failure on my
> machine occasionally today after this commit although I'll have to use it
> for a few days more before deciding whether it reduces the frequency of the
> failure or not.
>
> If it really is just a Windows thing rather than a lit thing I'm not sure
> what we'd be able to do beyond something like having lit intercept calls to
> rm and perform some sort of retry method for permission errors on Windows.
> I'm pretty sure that will work, but it's extremely nasty, and if the problem
> is more heinous than just Windows holding onto files it's not a real fix
> either.
>
> Thanks for having looked at this either way though!  It's a relief to know
> it's not just me that keeps running into this one.

Right, it's still failing intermittently :(

Indexer/AV seems like a more likely explanation and one that's going
to be hard to fix. Just working around 'rm' would fix this specific
tests, but there are others (archive-update.test) that also fail on
windows from time to time and that one seems unrelated to rm.

I rarely run tests on windows myself (takes forever) but I want the
buildbots to stop yelling at me ...

- Ben