[PATCH v2 0/2] t7900: fix flaky "maintenance.strategy" test

Hi,

I've recently noticed that t7900 is flaky, see for example [1].
The root cause of the flake is the auto-detaching logic of
git-maintenance(1), which sometimes causes us to skip maintenance
altogether when the foreground process is racing with background
maintenance.

Changes in v2:
  - Perform some word smithing on commit messages.
  - Link to v1: https://patch.msgid.link/20260807-pks-t7900-fix-flaky-test-v1-0-08d0ea0fbbc5@pks.im

Thanks!

Patrick

[1]: https://gitlab.com/gitlab-org/git/-/jobs/15762975482

---
Patrick Steinhardt (2):
      t7900: adapt some tests to use a throwaway repository
      t7900: fix flaky "maintenance.strategy" test

 t/t7900-maintenance.sh | 76 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 30 deletions(-)

Range-diff versus v1:

1:  10521f07ad ! 1:  1f3f8aa538 t7900: adapt some tests to use a throwaway repository
    @@ Commit message
         tests more neatly self-contained and allows us to trivially modify the
         environment in the next commit.
     
    +    Note that we adapt calls to `test_config ()` to use git-config(1)
    +    instead. This is because on the one hand we don't need the auto-revert
    +    logic of `test_config ()` as we're using a throwaway repository anyway.
    +    On the other hand it's not possible to use `test_config ()` as it uses
    +    `test_when_finished ()`, which errors out when we run it in a subshell.
    +
         Signed-off-by: Patrick Steinhardt [off-list ref]
     
      ## t/t7900-maintenance.sh ##
2:  71cb84a4a7 ! 2:  ba1fbb27f9 t7900: fix flaky "maintenance.strategy" test
    @@ Commit message
     
         But there's a second condition that may cause us to not execute tasks,
         namely when the "maintenance.lock" file exists due to a concurrently
    -    running tasks. We usually disable auto-maintenance from detaching in our
    -    test suite to avoid exactly these kinds of race conditions, but in t7900
    +    running git-maintenance(1) process. We usually disable auto-maintenance
    +    from detaching in our test suite to avoid exactly these kinds of race
    +    conditions by exporting `GIT_TEST_MAINT_AUTO_DETACH=false`. But in t7900
         we unset "GIT_TEST_MAINT_AUTO_DETACH" and thus enable the auto-detach
         logic. The intent of this is to exercise git-maintenance(1) closer to
         how it would run in a real-world scenario, but it does cause us to race

---
base-commit: 2c78326f810173a4f3aefd8021f1e07575412481
change-id: 20260807-pks-t7900-fix-flaky-test-160abfcef65a