`postgresql-libpq` 0.10.2.0 or higher won't build - where's the fix go?

[dten]

More of a question really for now.

since this MR postgresql-libpq has significantly changed how they find/register their native libpq dependency and haskell.nix seemingly no longer can find it.

I have a workaround to use locally which is just fix it myself (thanks for this feature)

packages.postgresql-libpq-configure.components.library.libs = pkgs.lib.mkForce [ pkgs.postgresql ];

However it would be very nice if everything did work, and i'm a little lost, so i'm looking for advice on where the fix should be.

The original code simply used to have extra-libraries: pq in the cabal file - which i can see hackage.nix maps to a postgresql dependency.

the new version instead has a new package which (as i read it) uses a setup: Configure to register the dependency from within the configure file.

At a guess hackage.nix has no clue about the Configure step's desire to have libpq before it's too late - which makes me think that it should still be in the postgresql-libpq-configure.cabal's extra-libraries

[amesgen]

One way to fix this is to tell postgresql-libpq to use pkg-config in cabal.project:

package postgresql-libpq
  flags: +use-pkg-config

[malteneuss]

@amesgen This helped me, thanks.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[endgame]

This is still an issue, and I think the fix at

haskell.nix/modules/hackage-quirks.nix

Lines 51 to 55 in ac4d743

	cabalProject = ''
	packages: .
	package postgresql-libpq
	flags: +use-pkg-config
	'';

should be put somewhere more general, as we're going to have a much better shot at getting a working build through pkg-config and NixOS/nixpkgs#370138 makes it sound like it's affecting main nixpkgs too, at least until the fix works its way through their CI.