cabalFlag of type string, instead of boolean

[peterbecich]

Can haskell-flake set a Cabal flag which is a string?
i.e. there is an issue with hackage-server which requires the flag --write-ghc-environment=always: isovector/type-errors#9

In this haskell-flake https://github.com/peterbecich/hackage-server/blob/enable-check/flake.nix I am trying to specify

hackage-server.cabalFlags.write-ghc-environment = "always";

Reading this it appears strings are not supported:

haskell-flake/nix/modules/project/settings/all.nix

Line 203 in 9173cc4

type = types.attrsOf types.bool;

Thanks

[srid]

I think you are conflating two things? cabal flags vs cabal build arguments.

You probably want extraBuildFlags

haskell-flake/nix/modules/project/settings/all.nix

Lines 183 to 189 in 9173cc4

	extraBuildFlags = {
	type = types.listOf types.str;
	description = ''
	Extra flags to pass to 'cabal build'
	'';
	impl = appendBuildFlags;
	};

[srid]

How do people normally pass --write-ghc-environment-files when using plain nixpkgs?

If we can answer that, I can implement it as an option in haskell-flake.

[peterbecich]

Looking, will follow up, thanks

[shivaraj-bh]

You could try extraConfigureFlags = [ “--write-ghc-environment=always” ];

[peterbecich]

good idea, thanks: https://github.com/haskell/hackage-server/blob/76b365c15f2ccce0cd42317f2e6b118e0873141d/flake.nix#L30

However, it rejects that:

.
> unrecognized 'configure' option `--write-ghc-environment=always'
.

[peterbecich]

This issue is not important, it is not worth your time. I am trying to get the DocTests to succeed for Hackage Server. However, write-ghc-environment will probably not solve it: haskell/hackage-server#1197 (comment)

Upgrading NixPkgs to GHC 9.8 is likely to solve it.

basePackages = pkgs.haskell.packages.ghc98;

That is blocked on other dependencies in NixPkgs.