Tests completely broken on MacOS

[olegrok]

See log https://gist.github.com/olegrok/a04e58bc94cd162bbe02cde10a5b2e24

Seems one moment we occupied all file descriptors

[rosik]

I've investigated the problem:

2. Default ulimit -n on macos is 256.
3. Luatest produces a lot of garbage fds for pipes and unix sockets

[olegrok]

Yes, it's so. I workarounded it in Mac OS CI https://github.com/tarantool/cartridge/pull/1110/files#diff-ffd0e8d632226f905ef8cdf81bcbbe1717163c00416566e344cabb454965e482R24

Also seems we should investigate Luatest as well. E.g. I suppose here https://github.com/tarantool/luatest/blob/0eb5d59d0b7a4da0fb0f237d760acbb264b959cb/luatest/ffi_io.lua#L51 old_fd could be closed (But I checked it, it didn't help in general). Another way - rewrite luatest with "popen" module.

[filonenko-mikhail]

So increasing ulimit seems solution now.
Last attempt:

• https://github.com/tarantool/cartridge/tree/tests-on-macos-2