Haskell in Nixpkgs/NixOS - Public Room Timeline

	Haskell in Nixpkgs/NixOS	720 Members
	For discussions and questions about Haskell with Nix, cabal2nix and haskellPackages in nixpkgs \| Current Docs: https://haskell4nix.readthedocs.io/ \| More Nix: #community:nixos.org \| More Haskell: #haskell-space:matrix.org	143 Servers

Load older messages

Sender	Message	Time
3 Jul 2025
woobilicious	brillant it worked, only issue was tests failing due to missing asset files, disabled tests and imports are working	17:37:26
	syd installs gentoo (they/them) joined the room.	18:46:50
syd installs gentoo (they/them)	Hey there! I hope some questions are appreciated. I'm trying to bump `nix-tree` (after asking the developer a while back to bump in hackage https://github.com/utdemir/nix-tree/issues/114#issuecomment-2888634183 ) assuming it would get updated eventually by nixos maintainers and the file says that you should use the regenerate-hackage-packages.sh but that fails on my local machine - I'd like to get in touch with the people maintaining that and assumed there was a Haskell Matrix channel maybe (there aren't a lot of GitHub issues around Hackage/Haskell lately if I'm not mistaken).	18:51:28
syd installs gentoo (they/them)	➜ nixpkgs git:(master) ✗ ./maintainers/scripts/haskell/regenerate-hackage-packages.sh --do-commit Obtaining Hackage data Generating compiler configuration Starting hackage2nix to regenerate pkgs/development/haskell-modules/hackage-packages.nix ... hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/webdriver-precore/0.1.0.2/webdriver-precore.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/ulid/0.3.3.0/ulid.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/tpdb/2.8.1/tpdb.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/singletons-base-code-generator/0.1/singletons-base-code-generator.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/singletons-base/3.5/singletons-base.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pty-mcp-server/0.0.4.0/pty-mcp-server.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-ui-response/0.0.3.0/pms-ui-response.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-ui-request/0.0.3.0/pms-ui-request.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-ui-notification/0.0.2.0/pms-ui-notification.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-infrastructure/0.0.4.0/pms-infrastructure.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-infra-watch/0.0.2.0/pms-infra-watch.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-infra-procspawn/0.0.1.0/pms-infra-procspawn.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-infra-cmdrun/0.0.2.0/pms-infra-cmdrun.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-domain-service/0.0.3.0/pms-domain-service.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-domain-model/0.0.4.0/pms-domain-model.cabal) hackage2nix: user error (cannot parse cabal file /nix/store/pv9625kwkhfj0bsgqc374by44ycm88cz-unpacked-cabal-hashes/pms-application-service/0.0.4.0/pms-application-service.cabal) hackage2nix: thread blocked indefinitely in an MVar operation	18:51:46
syd installs gentoo (they/them)	Reading the history of this channel I can see others also ran into `thread blocked indefinitely in an MVar operation`. I'm not sure if it the script is fully needed getting `nix-tree` usable again for others :).	18:53:34
syd installs gentoo (they/them)	https://github.com/NixOS/nixpkgs/issues/409085 ah I didn't get follow up github notifications. https://github.com/NixOS/nixpkgs/pull/409117#issuecomment-2895401376	18:55:05
syd installs gentoo (they/them)	Well at least I gave updating hackage packages a try for once, good to learn how that is done under the hood.	18:57:00
syd installs gentoo (they/them)	* Hey there! I've had some questions, I understand the situation now... Old message/thread: I'm trying to bump `nix-tree` (after asking the developer a while back to bump in hackage https://github.com/utdemir/nix-tree/issues/114#issuecomment-2888634183 ) assuming it would get updated eventually by nixos maintainers and the file says that you should use the regenerate-hackage-packages.sh but that fails on my local machine - I'd like to get in touch with the people maintaining that and assumed there was a Haskell Matrix channel maybe (there aren't a lot of GitHub issues around Hackage/Haskell lately if I'm not mistaken).	19:00:25
Teo (he/him)	I was profiling eval time of nixpkgs recently and I noticed that a lot of time was spent doing `hasPrefix` when evalling the haskell package set. I think this is caused by the hasPrefix call to check if stuff is part of amazonka and each call of `hasPrefix` re-checks if the needle is a path lol https://github.com/NixOS/nixpkgs/issues/419216 We could optimise the hasPrefix call, but maybe we should just add the list of amazonka packages to this file rather than traversing the entire haskell package set? https://github.com/NixOS/nixpkgs/blob/a44903b927ab16b829a76f51f84bca02a7f89a0f/pkgs/development/haskell-modules/configuration-common.nix#L3352	19:19:35
alexfmpe	I was profiling eval time of nixpkgs how does one even do this? I always wondered	20:24:38
Teo (he/him)	In reply to @alexfmpe:matrix.org I was profiling eval time of nixpkgs how does one even do this? I always wondered This is what I used https://github.com/NixOS/nix/pull/13220	20:30:51
alexfmpe	Ooooh	20:37:45
4 Jul 2025
lxsameer	hey folks,do we support cabal 3.14 for development?	15:16:38
alexfmpe	not sure what "for development" means, does this answer it? `$ nix-build -A cabal-install /nix/store/diig4i6ln0ia8xvv4kqs99klpjhlpzfl-cabal-install-3.14.2.0`	15:38:44
lxsameer	sorry for the confusion, apparently, cabal2nix does not like the `cabal-version: 3.14`	15:51:24
lxsameer	in a cabal file	15:51:28
maralorn	That was I think fixed very recently on the haskell-updates.	15:52:48
ners	I found a package that has outdated dependency bounds. Trying to build it with `doJailbreak` , I would expect it to either succeed or fail at compile time, but: `Configuring OTP-0.1.0.0... CallStack (from HasCallStack): withMetadata, called at libraries/Cabal/Cabal/src/Distribution/Simple/Utils.hs:368:14 in Cabal-3.10.3.0-ab3d:Distribution.Simple.Utils Error: Setup: Encountered missing or private dependencies: base >=4.5.0.0 && <4.14, bytestring >=0.9.2.0 && <0.11, time >=1.4 && <1.10`	16:40:27
alexfmpe	cabal2nix doesn't handle conditionals properly (for now), and the deps are behind a if, so they don't survive the conversion to .nix	17:01:15
alexfmpe	https://hackage.haskell.org/package/OTP-0.1.0.0/src/OTP.cabal	17:01:16
alexfmpe	You can workaround by shoving them in with addBuildDepends	17:01:41
alexfmpe	You can see examples in the configuration-ghcjs-9.x and configuration-darwin files	17:02:26
Collin Arnett	How can I get the haddoc html files for dependencies of my project when using `shellFor`? I have doHaddoc turned on for my dependencies.	18:35:27
alexfmpe	It's on by default I think?	19:35:28
alexfmpe	Easiest way is to run hoogle locally	19:35:41
alexfmpe	hoogle server --local -p 8080	19:36:18
alexfmpe	might need withHoogle = true, don't remember if default in shellFor	19:36:48
Collin Arnett	Does the hoogle server serve the haddocs as well? I'm not really sure what I'm looking for so I would like to browse the docs like I would on hackage.	20:44:03
Collin Arnett	Oh I see it does link them locally after you click on the package from hoogle. Thank you :D	20:49:02
5 Jul 2025
alexfmpe	is there a way for a nixpkgs-using project to apply an override to all haskell.packages.ghc123 like configuration-common.nix do? or do we always need the `nixpkgs.haskell.packages.${version}` override cascade ?	20:20:02

Show newer messages

Back to Room ListRoom Version: 6