Wrong packages being used when running yarn

[purefn]

I've got an SPA that I'm trying to build and can't quite get things worked out right. tslint and tsc fail when run with nix but are fine when I run yarn directly. After a bit of investigating, it appears to be a problem with the wrong versions of packages being used in the nix build.

It's a small subset of dependencies: date-fns, query-string, and a few others. I can't determine why these specifically are being singled out. I did some experimenting and found that, during the yarn install to create the yarn modules derivation, there is a /build/node_modules directory that is populated and a /build/deps/${pname}/node_modules directory that is created.

/build/node_modules contains all the dependencies of my package, with incorrect versions of date-fns, query-string and others.

/build/deps/${pname}/node_modules contains only subset of packages that have incorrect versions in build/node_modules, but has the correct versions of those packages.

I'm not doing anything out of the ordinary in my derivation

   client = mkYarnPackage {
      name = "portal-client";
      src = ../client;
      packageJSON = ../client/package.json;
      yarnLock = ../client/yarn.lock;

      postConfigure = ''
        substituteInPlace deps/$pname/tslint.json \
          --replace './node_modules/fp-ts/rules' "$node_modules/fp-ts/rules"
      '';

      buildPhase = ''
        yarn run build_qa
      '';
    };

Is there something different I should be doing?

[purefn]

The problem seems to be with the package.json that is put in /build. If I replace it with my actual package.json things work correctly. Possibly because there is also a workspace defined in mine and nested workspaces aren't supported?