How to ignore test dependencies from local package dependencies in shellFor?

[dten]

I'm using a stack project and shellFor and I've been struggling to target recent nightly snapshots.

I'm using persistent-postgresql which has a test component that depends on persistent-test which has dropped out of stackage and they don't plan on getting it back in. persistent-postgresql is in the nightly and I can successfully build and test my own package.

However, when using shellFor I end up with it refusing to build because of the transitive test dependencies.

I've tried various things such as setting doChecks = false, or using dontCheck to no avail. packages = ps: []; let the shell load but I assume misses the point. Given that, I thought packages = ps: builtins.attrValues (pkgs.haskell-nix.haskellLib.selectProjectPackages ps); would help but it results in the same error.

Thanks for any assistance you can offer.

error:
       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:34:12:
           33|
           34|   strict = derivationStrict drvAttrs;
             |            ^
           35|

       … while evaluating derivation 'ghc-shell-for-packages'
         whose name attribute is located at /nix/store/g1wkcpwadmnn20lwbik5kfwnvfrc6ahi-source/pkgs/stdenv/generic/make-derivation.nix:716:13

       … while evaluating attribute 'CABAL_CONFIG' of derivation 'ghc-shell-for-packages'
         at /nix/store/hhmh6a99xh0r6wkphbpbvrn1iazg4nzz-source/builder/shell-for.nix:210:5:
          209|   } // lib.optionalAttrs exactDeps {
          210|     CABAL_CONFIG = "${ghcEnv.drv}/configFiles/cabal.config";
             |     ^
          211|   })

       … while evaluating the option `packages.persistent-postgresql.components.tests.test.depends':

       … while evaluating definitions from `/nix/store/hhmh6a99xh0r6wkphbpbvrn1iazg4nzz-source/modules/plan.nix':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: The Haskell package set does not contain the package: persistent-test (build dependency).
       If you are using Stackage, make sure that you are using a snapshot that contains the package. Otherwise you may need to update the Hackage snapshot you are using, usually by updating haskell.nix.

[hamishmack]

With a cabal.project this should be automatic if the tests are disabled for the package in the cabal.project, cabalProjectLocal or by passing configureArgs = "--disable-tests --disable-benchmarks" to the project function.

However I think for a stack.yaml based project I am not sure how to work around this. Can you add persistent-test to the stack.yaml like this?

extra-deps:
- persistent-test-2.13.1.4

[dten]

Thanks that does work for this case.

I dug more into why it was happening since you said it should be automatic. The issue seems to stem from trying to cache the shell build inputs as per https://nixos.wiki/wiki/Caching_nix_shell_build_inputs .

I found CI is essentially calling nix-build shell.nix -A inputDerivation and that's when the error occurs. I assume this doesn't understand that doChecks is off and so the tests dependencies aren't interesting.

Perhaps interestingly nix build -f shell.nix inputDerivation does build without complaint but to be honest I'm sure not if it's equivalent at all.