Right now I use the gcc, git, vim, and ninja APE binaries on my local system for daily work, and so far I have seen no visible regressions.

I agree with you though -- an extensive testing setup will reveal more things for improvement, be it in my patch or in the libc itself. At the moment I only have direct access to Debian 11/Fedora 35/FreeBSD 13, but I expect we will soon find a nice way to run tests across the different operating systems automatically. One of my ideas was to setup a separate drive or folder with all the executables, accessible from different operating systems/VMs, and then run the tests from each. What do you think?

I don't know enough about APE or cosmo to know how risky the changes are.

Here apparently the changes are mostly related to error handling, and I guess that's not something that's very well tested with normal usage.

I think github actions has windows images