Specifying dependency which has a flake

[pmiddend]

I have a Haskell package on GitHub which has a flake.nix in it and a packages.default defined via callCabal2nix. I'd like to specify this as a dependency to my other flake-based Haskell project. However:

inputs = { myhdf5.url = "github:pmiddend/hs-hdf5/upgrade-bytestring-primitive-new-name"; }

and then

packages = {
  hdf5.source = inputs.myhdf5;
};

Does not work:

error:
       … while evaluating an expression to select 'drvPath' on it
         at «internal»:1:552:
       … while evaluating strict
         at «internal»:1:552:
       (stack trace truncated; use '--show-trace' to show the full trace)

       error: infinite recursion encountered
       at «internal»:1:490:

The overarching problem here might be that the package on hackage is called "hdf5", and it pkgconfigDepends on hdf5 (see https://github.com/picca/hs-hdf5/blob/devel/hdf5.cabal#L126). But that must be pkgs.hdf5, the C library, not haskellPackages.hdf5.

I have no idea how to debug or even fix this. The flake for my hdf5 project fixes this by specifying hdf5 = pkgs.hdf5 in the input, so I thought I could easily plug it into the other flake and be done with it.

[srid]

haskell-flake provides the "output" project module that you can import:

https://community.flake.parts/haskell-flake/modules#default