haskellPackages.mkDerivation: show test outputs as they happen

[sternenseemann]

Currently, the test output is only printed if the test suite fails. If a
test suite gets stuck, however, and is hit with a timeout by Hydra, it
can help to have the log available when diagnosing the issue.

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.05 Release Notes (or backporting 21.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[maralorn]

Sounds like a good idea. Have you tried this on some packages? Won‘t it be too spamy?

[sternenseemann]

Sure, depending on the test suite. Spammy is, however, a trend with the decisions taken in generic-builder.nix (e.g. high Cabal configure verbosity).

[sternenseemann]

@ofborg eval

[roberth]

spammy?

The experimental CLI hides logs by default, if that's any consolation.

Having no logs hurts more than having too much of it, so 👍 .

[maralorn]

Okay! I suggest merging this in after next haskell-updates merge.

[sternenseemann]

(Could be bundled with the other set rebuild PR.)

[maralorn]

Thank you!