gitlab-ci: disable RAM disk on macOS jobs

When we added the macOS jobs to GitLab CI in 56090a35ab (ci: add macOS
jobs to GitLab CI, 2024-01-18) we had to work around some very slow
disks. This workaround essentially creates a RAM disk that we mount,
where all test data is being written into RAM instead of the real disk.

In the next commit though we're about to enable "GIT_TEST_LONG", which
will make tests run that are marked with the "EXPENSIVE" prerequisite.
This change will make a couple of tests run that write up to 8GB of data
into the test output directory. As our RAM disk is only 4GB in size,
this change will cause ENOSPC errors.

We could accommodate for this by increasing the size of the RAM disk.
In c9d708b7fc (gitlab-ci: upgrade macOS runners, 2026-05-21) we have
upgraded our runners to use the "large" runners, which have 16GB of RAM
available. So we could easily expand the RAM disk to a capacity of for
example 12GB. But some test runs have shown that this is still quite
flaky overall, as we get quite close to our limits.

Instead, drop the workaround completely. This does indeed slow down
execution of the test jobs:

  - osx-clang goes from 18 minutes to 25 minutes

  - osx-meson goes from 21 minutes to 33 minutes

  - osx-reftable stays at 21 minutes

The last one seems like an outlier. The only explanation that I have is
that we end up writing significantly less files with the reftable
backend, which ultimately causes less I/O.

Overall though, it's preferable to have something that works with the
least amount of flakiness compared to having something else that is
faster but unstable. Despite that, the macOS jobs aren't even the
slowest jobs, so this doesn't extend the overall pipeline's length.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1a8e90932cc292b74d663ceeec8d4cc060e67c2e..a4aebe8b719ca8e1b84c8dffeea578df9d0a54b4 100644 (file)
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -88,13 +88,8 @@ test:osx:
   tags:
     - saas-macos-large-m2pro
   variables:
-    TEST_OUTPUT_DIRECTORY: "/Volumes/RAMDisk"
+    TEST_OUTPUT_DIRECTORY: "/tmp/test-output"
   before_script:
-    # Create a 4GB RAM disk that we use to store test output on. This small hack
-    # significantly speeds up tests by more than a factor of 2 because the
-    # macOS runners use network-attached storage as disks, which is _really_
-    # slow with the many small writes that our tests do.
-    - sudo diskutil apfs create $(hdiutil attach -nomount ram://8192000) RAMDisk
     - ./ci/install-dependencies.sh
   script:
     - ./ci/run-build-and-tests.sh