Re: t7527 intermittent failure on macOS APFS and possible fix

[Jeff King <peff@peff.net>]

On Fri, Aug 12, 2022 at 08:52:24PM +0700, Đoàn Trần Công Danh wrote:

> Running t7527 on macOS with encrypted APFS filesystem.
> I observes intermittent failure, however, when I manually check the
> test cases, they're all passed.
> 
> I suspected fileystem caching issue.
> I added those sync-s into test steps and the test pass.
> I'm not sure if this is the intending "fix" for the tests
> since we're testing the fsmonitor with t7527.

I don't know anything about your problem area, but some tools in our
test suite that might help you get better results with an intermittent
problem (if you didn't already know about them):

  - add:

      GIT_TEST_OPTS = -x --verbose-log

    into config.mak. Then when a "make test" run fails, you can see the
    log in t/test-results/t7527-*.out.

  - try running:

      ./t7527-* --stress

    which will run a bunch of instances simultaneously, with the idea
    that the load will introduce timing issues that will trigger the
    bug. The failed instance will produce a detailed log on stdout.

That might help you get more output from the failing cases.

-Peff