| 15 Sep 2025 |
 Alex | Nope, build time. | 13:55:29 |
 emily | but that's not C | 13:55:39 |
| emily | I mean it's Hugs outputting that right | 13:55:50 |
| emily | so it's Hugs runtime | 13:55:55 |
| Alex | The NotReallyAType comes from base's autoconf script somehow not finding the corresponding Haskell type for a few C types. | 13:56:31 |
| emily | I see | 13:58:14 |
| emily | probably there are new warnings/errors in GCC confusing it | 13:58:32 |
| emily | that happens a lot in autoconf | 13:58:41 |
| emily | check config.log | 13:58:43 |
| emily | you'll probably see some ancient looking C program that needs adapting | 13:58:56 |
| emily | you should of course autoreconfHook and get it on latest autotools | 13:59:10 |
| Alex | Thanks for the advice. I'll take a look when I get to work on the PRs. | 14:05:39 |
 bglgwyng | I realized that I diagnosed the issue wrong | 15:02:06 |
| bglgwyng | {
packages.zlib1 = (pkgs.haskellPackages.zlib).override { zlib = pkgs.zlib; };
# it works
packages.zlib2 = (pkgs.haskellPackages.callCabal2nix "zlib" inputs.zlib-src { }).override { zlib = pkgs.zlib; };
# it works
packages.splitmix1 = (pkgs.haskellPackages.splitmix).override { testu01 = null; };
# it doesn't work
packages.splitmix2 = (pkgs.haskellPackages.callCabal2nix "splitmix" inputs.splitmix-src { }).override { testu01 = null; };
};
Only the last one failed with 'error: function 'anonymous lambda' called without required argument 'testu01''
| 15:02:33 |
| bglgwyng | Here is the reproducer https://github.com/bglgwyng/haskellPackages-override | 15:02:59 |
| bglgwyng | * {
packages.zlib1 = (pkgs.haskellPackages.zlib).override { zlib = pkgs.zlib; };
# it works
packages.zlib2 = (pkgs.haskellPackages.callCabal2nix "zlib" inputs.zlib-src { }).override { zlib = pkgs.zlib; };
# it works
packages.splitmix1 = (pkgs.haskellPackages.splitmix).override { testu01 = null; };
# it doesn't work
packages.splitmix2 = (pkgs.haskellPackages.callCabal2nix "splitmix" inputs.splitmix-src { }).override { testu01 = null; };
};
Only the last one failed with error: function 'anonymous lambda' called without required argument 'testu01'
| 15:03:21 |
| bglgwyng | I can see testu01 in the arguments of cabal2nix-splitmix, but somehow the override failed. | 15:04:08 |
 keypusher | I have a hard time getting protoc (on the PATH) while building a package with callCabal2Nix. It's used by cabal extension. | 15:20:20 |
| keypusher | Are there any tricks to troubleshooting that? | 15:21:06 |
 sterni | keypusher: cabal2nix does not really have the ability to do that automatically since Cabal does not allow specifying a dependency on a build tool that is not itself a Cabal package. You need to use addBuildTools or the like from haskell.lib.compose. | 15:32:07 |
| sterni | bglgwyng: on what system does packages.splitmix2 fail to evaluate? | 15:36:34 |
| keypusher | Oh ok. I tried googling "haskell.lib.compose addBuildtools" but came up a bit short. You don't happen to have some useful url? | 15:37:31 |
| keypusher | thanks btw! | 15:37:53 |
| sterni | bglgwyng: the testu01 test suite is only buildable on linux, Cabal discards this dependency on non-linux, you can force the platform to use with e.g. --system x86_64-linux | 15:38:40 |
| sterni | keypusher: https://nixos.org/manual/nixpkgs/stable/#haskell-trivial-helpers | 15:39:11 |
| bglgwyng | it's x86_64-linux | 15:52:22 |
| bglgwyng | I haven't trie don the other platforms | 15:53:24 |
| sterni | cabal2nix --system x86_64-linux https://hackage.haskell.org/package/splitmix-0.1.3.1.tar.gz gives me
{ mkDerivation, async, base, base-compat-batteries, bytestring
, containers, criterion, deepseq, fetchzip, HUnit, lib
, math-functions, process, random, template-haskell, test-framework
, test-framework-hunit, testu01, tf-random, vector
}:
mkDerivation {
pname = "splitmix";
version = "0.1.3.1";
src = fetchzip {
url = "https://hackage.haskell.org/package/splitmix-0.1.3.1.tar.gz";
sha256 = "0mll5axdvh5wan6prh3v6l2n15xsj31ghi0g887ljpk515id5a2w";
};
libraryHaskellDepends = [ base deepseq ];
testHaskellDepends = [
async base base-compat-batteries bytestring containers deepseq
HUnit math-functions process random template-haskell test-framework
test-framework-hunit tf-random vector
];
testSystemDepends = [ testu01 ];
benchmarkHaskellDepends = [
base containers criterion random tf-random
];
description = "Fast Splittable PRNG";
license = lib.licenses.bsd3;
}
So this looks fine.
| 15:54:59 |
| sterni | ahh now I understand the issue. | 15:56:50 |
| sterni | The problem with override is that it depends on initially computing the derivation successfully. This doesn't work if an argument is missing which is the case here with testu01. That's why callCabal2nix has a third argument to pass in arguments (which can also act as an override at the definition site). So you want to do:
(pkgs.haskellPackages.callCabal2nix "splitmix" (builtins.fetchTarball "https://hackage.haskell.org/package/splitmix-0.1.3.1.tar.gz") { testu01 = null /* just pass something */; }).override { testu01 = /* later we can pass something else: */ my-pkg; }
| 15:59:14 |
