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Diffstat (limited to 'doc/languages-frameworks/haskell.section.md')
| -rw-r--r-- | doc/languages-frameworks/haskell.section.md | 148 |
1 files changed, 65 insertions, 83 deletions
diff --git a/doc/languages-frameworks/haskell.section.md b/doc/languages-frameworks/haskell.section.md index dde55c329a4ac..e8970b2d03354 100644 --- a/doc/languages-frameworks/haskell.section.md +++ b/doc/languages-frameworks/haskell.section.md @@ -21,25 +21,14 @@ Many “normal” user facing packages written in Haskell, like `niv` or `cachix are also exposed at the top level, and there is nothing Haskell specific to installing and using them. -All of these packages are originally defined in the `haskellPackages` package -set and are re-exposed with a reduced dependency closure for convenience. -(see `justStaticExecutables` or `separateBinOutput` below) +All of these packages are originally defined in the `haskellPackages` package set. +The same packages are re-exposed with a reduced dependency closure for convenience (see `justStaticExecutables` or `separateBinOutput` below). -The `haskellPackages` set includes at least one version of every package from -Hackage as well as some manually injected packages. This amounts to a lot of -packages, so it is hidden from `nix-env -qa` by default for performance reasons. -You can still list all packages in the set like this: +:::{.note} +See [](#chap-language-support) for techniques to explore package sets. +::: -```console -$ nix-env -f '<nixpkgs>' -qaP -A haskellPackages -haskellPackages.a50 a50-0.5 -haskellPackages.AAI AAI-0.2.0.1 -haskellPackages.aasam aasam-0.2.0.0 -haskellPackages.abacate abacate-0.0.0.0 -haskellPackages.abc-puzzle abc-puzzle-0.2.1 -… -``` -Also, the `haskellPackages` set is included on [search.nixos.org]. +The `haskellPackages` set includes at least one version of every package from [Hackage](https://hackage.haskell.org/) as well as some manually injected packages. The attribute names in `haskellPackages` always correspond with their name on Hackage. Since Hackage allows names that are not valid Nix without escaping, @@ -49,8 +38,7 @@ For packages that are part of [Stackage] (a curated set of known to be compatible packages), we use the version prescribed by a Stackage snapshot (usually the current LTS one) as the default version. For all other packages we use the latest version from [Hackage](https://hackage.org) (the repository of -basically all open source Haskell packages). See [below](#haskell-available- -versions) for a few more details on this. +basically all open source Haskell packages). See [below](#haskell-available-versions) for a few more details on this. Roughly half of the 16K packages contained in `haskellPackages` don’t actually build and are [marked as broken semi-automatically](https://github.com/NixOS/nixpkgs/blob/haskell-updates/pkgs/development/haskell-modules/configuration-hackage2nix/broken.yaml). @@ -63,68 +51,15 @@ How you can help with that is described in [Fixing a broken package](#haskell-fixing-a-broken-package). --> -`haskellPackages` is built with our default compiler, but we also provide other -releases of GHC and package sets built with them. You can list all available -compilers like this: +`haskellPackages` is built with our default compiler, but we also provide other releases of GHC and package sets built with them. +Available compilers are collected under `haskell.compiler`. -```console -$ nix-env -f '<nixpkgs>' -qaP -A haskell.compiler -haskell.compiler.ghc810 ghc-8.10.7 -haskell.compiler.ghc90 ghc-9.0.2 -haskell.compiler.ghc925 ghc-9.2.5 -haskell.compiler.ghc926 ghc-9.2.6 -haskell.compiler.ghc927 ghc-9.2.7 -haskell.compiler.ghc92 ghc-9.2.8 -haskell.compiler.ghc945 ghc-9.4.5 -haskell.compiler.ghc946 ghc-9.4.6 -haskell.compiler.ghc947 ghc-9.4.7 -haskell.compiler.ghc94 ghc-9.4.8 -haskell.compiler.ghc963 ghc-9.6.3 -haskell.compiler.ghc96 ghc-9.6.4 -haskell.compiler.ghc98 ghc-9.8.1 -haskell.compiler.ghcHEAD ghc-9.9.20231121 -haskell.compiler.ghc8107Binary ghc-binary-8.10.7 -haskell.compiler.ghc865Binary ghc-binary-8.6.5 -haskell.compiler.ghc924Binary ghc-binary-9.2.4 -haskell.compiler.integer-simple.ghc8107 ghc-integer-simple-8.10.7 -haskell.compiler.integer-simple.ghc810 ghc-integer-simple-8.10.7 -haskell.compiler.native-bignum.ghc90 ghc-native-bignum-9.0.2 -haskell.compiler.native-bignum.ghc902 ghc-native-bignum-9.0.2 -haskell.compiler.native-bignum.ghc925 ghc-native-bignum-9.2.5 -haskell.compiler.native-bignum.ghc926 ghc-native-bignum-9.2.6 -haskell.compiler.native-bignum.ghc927 ghc-native-bignum-9.2.7 -haskell.compiler.native-bignum.ghc92 ghc-native-bignum-9.2.8 -haskell.compiler.native-bignum.ghc928 ghc-native-bignum-9.2.8 -haskell.compiler.native-bignum.ghc945 ghc-native-bignum-9.4.5 -haskell.compiler.native-bignum.ghc946 ghc-native-bignum-9.4.6 -haskell.compiler.native-bignum.ghc947 ghc-native-bignum-9.4.7 -haskell.compiler.native-bignum.ghc94 ghc-native-bignum-9.4.8 -haskell.compiler.native-bignum.ghc948 ghc-native-bignum-9.4.8 -haskell.compiler.native-bignum.ghc963 ghc-native-bignum-9.6.3 -haskell.compiler.native-bignum.ghc96 ghc-native-bignum-9.6.4 -haskell.compiler.native-bignum.ghc964 ghc-native-bignum-9.6.4 -haskell.compiler.native-bignum.ghc98 ghc-native-bignum-9.8.1 -haskell.compiler.native-bignum.ghc981 ghc-native-bignum-9.8.1 -haskell.compiler.native-bignum.ghcHEAD ghc-native-bignum-9.9.20231121 -haskell.compiler.ghcjs ghcjs-8.10.7 -``` - -Each of those compiler versions has a corresponding attribute set built using +Each of those compiler versions has a corresponding attribute set `packages` built with it. However, the non-standard package sets are not tested regularly and, as a result, contain fewer working packages. The corresponding package set for GHC 9.4.5 is `haskell.packages.ghc945`. In fact `haskellPackages` is just an alias for `haskell.packages.ghc964`: -```console -$ nix-env -f '<nixpkgs>' -qaP -A haskell.packages.ghc927 -haskell.packages.ghc927.a50 a50-0.5 -haskell.packages.ghc927.AAI AAI-0.2.0.1 -haskell.packages.ghc927.aasam aasam-0.2.0.0 -haskell.packages.ghc927.abacate abacate-0.0.0.0 -haskell.packages.ghc927.abc-puzzle abc-puzzle-0.2.1 -… -``` - Every package set also re-exposes the GHC used to build its packages as `haskell.packages.*.ghc`. ### Available package versions {#haskell-available-versions} @@ -923,14 +858,61 @@ for this to work. `justStaticExecutables drv` : Only build and install the executables produced by `drv`, removing everything -that may refer to other Haskell packages' store paths (like libraries and -documentation). This dramatically reduces the closure size of the resulting -derivation. Note that the executables are only statically linked against their -Haskell dependencies, but will still link dynamically against libc, GMP and -other system library dependencies. If dependencies use their Cabal-generated -`Paths_*` module, this may not work as well if GHC's dead code elimination -is unable to remove the references to the dependency's store path that module -contains. + that may refer to other Haskell packages' store paths (like libraries and + documentation). This dramatically reduces the closure size of the resulting + derivation. Note that the executables are only statically linked against their + Haskell dependencies, but will still link dynamically against libc, GMP and + other system library dependencies. + + If a library or its dependencies use their Cabal-generated + `Paths_*` module, this may not work as well if GHC's dead code elimination is + unable to remove the references to the dependency's store path that module + contains. + As a consequence, an unused reference may be created from the static binary to such a _library_ store path. + (See [nixpkgs#164630][164630] for more information.) + + Importing the `Paths_*` module may cause builds to fail with this message: + + ``` + error: output '/nix/store/64k8iw0ryz76qpijsnl9v87fb26v28z8-my-haskell-package-1.0.0.0' is not allowed to refer to the following paths: + /nix/store/5q5s4a07gaz50h04zpfbda8xjs8wrnhg-ghc-9.6.3 + ``` + + If that happens, first disable the check for GHC references and rebuild the + derivation: + + ```nix + pkgs.haskell.lib.overrideCabal + (pkgs.haskell.lib.justStaticExecutables my-haskell-package) + (drv: { + disallowGhcReference = false; + }) + ``` + + Then use `strings` to determine which libraries are responsible: + + ``` + $ nix-build ... + $ strings result/bin/my-haskell-binary | grep /nix/store/ + ... + /nix/store/n7ciwdlg8yyxdhbrgd6yc2d8ypnwpmgq-hs-opentelemetry-sdk-0.0.3.6/bin + ... + ``` + + Finally, use `remove-references-to` to delete those store paths from the produced output: + + ```nix + pkgs.haskell.lib.overrideCabal + (pkgs.haskell.lib.justStaticExecutables my-haskell-package) + (drv: { + postInstall = '' + ${drv.postInstall or ""} + remove-references-to -t ${pkgs.haskellPackages.hs-opentelemetry-sdk} + ''; + }) + ``` + +[164630]: https://github.com/NixOS/nixpkgs/issues/164630 `enableSeparateBinOutput drv` : Install executables produced by `drv` to a separate `bin` output. 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