Modifying test parameters in llvm derivation

I’m not sure if this is a correct place to ask as I run into problems with nix build scripts rather than NixOS.

What I experience is that my build depends on rustc which in turn depends on llvm, when doing a clean build llvm performs tests and doesn’t output any intermediate results for about 20 minutes. This makes CI think that the build is stuck and stop the process.

I found that there is a way to make lit that runs tests output intermediate results with -a flag, but I can’t understand where or how should I do that.

I might try to make a minimal example, but that may prove a bit complicated as I am not too fluent in Nix. My build depends on nix-cross-overlay which depends on rust-overlay

Upd: I found that I may modify the timeout to accommodate longer running tests with --max-silent-time but I can’t understand how and where to pass it to the CI

Upd2: I’ve passed NIX_CONFIG: ‘max-silent-time = 1’ to the run, and also found where we set max-silent-time in CI configuration (not too straightforward), but I am still interested in the way to set verbosity of llvm tests, if that exists and doesn’t require to patch everything manually (even then it might be useful for someone)