Reproduction steps

1. Be on Mac OS
2. Clone libgit2 from: https://github.com/implausible/libgit2/tree/repro/slow-clone-mac-os
3. Build libgit2
4. run the test suite online::slow::clone.

Expected behavior

The test suite should finish in 10 seconds. Note, I've also added
https://github.com/implausible/libgit2/tree/repro/fast-clone-mac-os which has the same test suite built before #5286 was merged. Running that on Mac OS, the suite finishes in <10s.

Actual behavior

The test suite finishes in 2 to 3 minutes. This behavior is completely isolated to Mac OS.

Version of libgit2 (release number or SHA1)

I've tracked the change to 4460bf40c9e935acb853b5d61279a50014ede0b3 or #5286. This is still slow in 0.99.0.

Operating system(s) tested

Mac OS
Linux
Windows