Description
Summary
In the version of libgit2 bundled with kubuntu 25.04 (1.9.0+ds-1ubuntu1) there is an enormous performance regression compared with the version bundled with 24.10. I built the library myself to narrow the issue down. I conducted a binary search of git commits and narrowed it down to fb1797d, which is the first commit that shows the problem: the parent 93c9444 is fine. (These are between the v1.8.0 and v1.8.1 tags.)
Reproduction
Using kubuntu 25.04 (I have tested with a clean installation):
- Clone the libgit2 repository
- Check out revision 93c9444 and build
- Run ctest -V. Time is normal: my output is here ctest-93c94.txt and the overall time is 194.92 s.
- Check out revision fb1797d and build
- Run ctest -V. Time is extremely slow: my output is here ctest-fb1797.txt and the overall time is 996.67 s.
The biggest slowdowns occur in the online::badssl test (test 3 goes from 34.08 s to 434.25 s most of which time was stuck on the badssl test) and test 10 auth_clone which goes from 2.58 s to 402.93 s.
This is absolutely crippling performance in applications that use libgit2, for example Siril uses it to clone or fetch a repository at startup and it has gone from being unnoticeable (< 1 s) to taking approx. 6 minutes.
I'll be happy to provide any further help in terms of testing things, just let me know.