is there a way to make a non-fixed-output derivation with buildGoModule?
I have a package with dependencies that need to be patched to point to nix store

  packages = rec {
    env86 = pkgs.buildGoModule {
      name = "env86";
      # TODO: Real version
      version = "1";
      src = ./.;
      buildInputs = with pkgs; [
        gtk3
      ];


      # HACK: this package uses purego to link libraries at runtime,
      # which will fail since we have no global libs, patch the library
      # paths to point to nix store
      modPostBuild = ''
        sed -i 's|"libgtk-3.so"|"${pkgs.gtk3}/lib/libgtk-3.so"|' vendor/tractor.dev/toolkit-go/desktop/linux/linux.go
      '';
      vendorHash = pkgs.lib.fakeHash;
      outputHashMode = null;
      outputHashAlgo = null;
      outputHash = null;

      # HACK: guest86 needs to be built externally
      preBuild = ''
        rm -r cmd/guest86
      '';
    };
    default = env86;

  };

but this still results in illegal path references in fixed-output derivation