lib/tests: Use --option to enable abort-on-warn

[Tom-Hubrecht]

Correctly set the abort-on-warn option in the modules.sh tests.

Note that checkConfigError 'The deprecated .*functor.wrappedattribute .*is accessed, use.*nestedTypes.elemType instead.' options.attrsWith.type.functor.wrapped ./deprecated-wrapped.nix still errors out when abort-on-warn = false because it tries to serialize thunks (and if forced would serialize lambdas)

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

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[roberth]

Weird, I made it intentionally compatible with the old lib.warn.

$ NIX_ABORT_ON_WARN=1 nix-instantiate --eval --expr 'builtins.warn "hoi" null'
evaluation warning: hoi
error:
       … while calling the 'warn' builtin
         at «string»:1:1:
            1| builtins.warn "hoi" null
             | ^

       error: aborting to reveal stack trace of warning, as abort-on-warn is set

[lf-]

yeah this looks good to me.

[lf-]

Weird, I made it intentionally compatible with the old lib.warn.

$ NIX_ABORT_ON_WARN=1 nix-instantiate --eval --expr 'builtins.warn "hoi" null'
evaluation warning: hoi
error:
       … while calling the 'warn' builtin
         at «string»:1:1:
            1| builtins.warn "hoi" null
             | ^

       error: aborting to reveal stack trace of warning, as abort-on-warn is set

I know you did, but we want to get rid of environment variables, and the Lix implementation of builtins.warn isn't going to support the legacy environment variable.

[roberth]

Ok I guess

[RaitoBezarius]

the Lix implementation of builtins.warn isn't going to support the legacy environment variable.

it doesn't.

❯ NIX_ABORT_ON_WARN=1 nix-instantiate --eval --expr 'builtins.warn "hoi" null'                            
warning: hoi
null

[Tom-Hubrecht]

This would also need a backport to 25.11

[nixpkgs-ci]

Successfully created backport PR for release-25.11:

• [Backport release-25.11] lib/tests: Use --option to enable abort-on-warn #469240