flake: Ignore broken packages for checks and hyrda

flake.nix

@@ -71,21 +71,29 @@
         linuxSystem = "x86_64-linux";
         pkgs = importNixpkgs linuxSystem [self.overlays.default];
         treefmtEval = loadTreefmt pkgs;
+
+        # A function that removes packages that are known to
+        # have issues from a set of packages.
+        # Packages that are known to have issues, and should not
+        # be built by `nix flake check` or Hydra.
+        # Mark every entry with a GitHub issue that tracks
+        # respective issues.
+        filterBroken = nixpkgs.lib.filterAttrs (_: x: !x.meta.broken);
       in {
         # Github Actions executes `nix flake check` therefore this output
         # should only contain derivations that can built within CI.
         # See `.github/workflows/ci.yaml`.
         checks.${linuxSystem} =
           # For `nix flake check` to *build* all packages, because by default
           # `nix flake check` only evaluates packages and does not build them.
-          self.packages.${linuxSystem}
+          (filterBroken self.packages.${linuxSystem})
           // {
             formatting = treefmtEval.config.build.check self;
           };
 
         # To generate a Hydra jobset for CI builds of all packages.
         # See <https://hydra.ngi0.nixos.org/jobset/ngipkgs/main>.
-        hydraJobs.packages.${linuxSystem} = self.packages.${linuxSystem};
+        hydraJobs.packages.${linuxSystem} = (filterBroken self.packages.${linuxSystem});
 
         # `nixosTests` is a non-standard name for a flake output.
         # See <https://github.com/ngi-nix/ngipkgs/issues/28>.

pkgs/liberaforms/default.nix

@@ -43,4 +43,6 @@ in
 
       shutdownPostgres
     '';
+
+    meta.broken = true;  # See <https://github.com/ngi-nix/ngipkgs/issues/40>.
   }

pkgs/liberaforms/env.nix

@@ -40,4 +40,13 @@
     ${extraReq}
   '';
 in
-  mach-nix.mkPython {inherit requirements;}
+  (mach-nix.mkPython {
+    inherit requirements;
+  }).overrideAttrs (_: {
+    # NOTE: Probably this override could also be
+    # done via the `_` argument for `mach-nix.mkPython`,
+    # see <https://github.com/DavHau/mach-nix/tree/725aab8d52eb2f5b8ff67bea61049011ef31597c#optional-arguments>,
+    # but this works too, and we do not have to think about
+    # what `{package}` means.
+    meta.broken = true;  # See <https://github.com/ngi-nix/ngipkgs/issues/40>.
+  })