stackage2nix
converts a Stack file into a Nix Haskell packages set.
It creates LTS Stackage packages set, and applies appropriate overrides on top of it.
You can install stackage2nix
from the Nix expression:
nix-env -i -f ./nix/stackage2nix
It provides pre-configured wrapper around the raw executable with runtime
PATH
and all auxiliary flags set up.
stackage2nix \
--lts-haskell "$LTS_HASKELL_REPO" \
--all-cabal-hashes "$ALL_CABAL_HASHES_REPO" \
.
stackage2nix
has three required arguments:
--lts-haskell
- path to fpco/lts-haskell--all-cabal-hashes
- path to commercialhaskell/all-cabal-hashes checked out tohackage
branch.
- path to stack.yaml file or directory
Produced Nix derivation split on following files:
- packages.nix - Base Stackage packages set
- configuration-packages.nix - Compiler configuration
- default.nix - Final Haskell packages set with all overrides applied
A particular package from result Haskell packages set can be built with:
nix-build -A <package-name>
See also the blog post about history and motivation behind the project.
nix-env
is required to be on PATH by the distribution-nixpkgs dependencynix-prefetch-scripts
is required on PATH if you have git dependencies instack.yaml
Complex projects may require some extra customization.
Snippet override.nix
below shows a minimal example of how to apply additional
overrides on top of Haskell packages set produced by stackage2nix
.
with import <nixpkgs> {};
with pkgs.haskell.lib;
let haskellPackages = import ./. {};
in haskellPackages.override {
overrides = self: super: {
stackage2nix = disableSharedExecutables super.stackage2nix;
};
}
nix-build -A stackage2nix override.nix
For more complex overrides and detailed information on how to work with Haskell packages in Nix, see Nixpkgs manual User’s Guide to the Haskell Infrastructure
For other examples of stackage2nix
usage, see 4e6/stackage2nix-examples repository.
It verifies stackage2nix
by running it on different public projects.