Our project has a test suite running bunch of e2e/integration tests. I’ve just noticed that on my system somehow running it inside nix derivation is much slower than running it directly in the dev shell. I don’t think it was like that before. I recently updated my system to nixos-unstable, in anticipation of nixos-25.11, but I’m not yet sure if it is related.
The test suite is very networking heavy, so this somehow could be network-related, because I don’t really see the compilation itself being slower.
If anyone has any ideas, that would be much appreciated.