stackage2nix
stackage2nix
converts a Stack file into a Nix Haskell packages set.
Create build derivation from stack.yaml
Generate targets from stack.yaml only
stack exec -- stackage2nix .
Command creates file default.nix
which overrides haskell.packages.stackage
packages set. You should use
typeable/nixpkgs-stackage overlay that
adds LTS Stackage packages to Nixpkgs.
Build package with overlay installed:
nix-build -A stackage2nix
Generate Stackage packages for the build
If you don't want to use Stackage overlay, stackage2nix can generate required
packages with --with-stackage-closure
flag.
stack exec -- stackage2nix \
--all-cabal-hashes /path/to/commercialhaskell/all-cabal-hashes \
--lts-haskell /path/to/fpco/lts-haskell \
--with-stackage-closure \
./stack.yaml
To generate Stackage packages, you should supply additional
--all-cabal-hashes
and --lts-haskell
flags that points to
commercialhaskell/all-cabal-hashes
checked out to hackage
branch and
fpco/lts-haskell respectively.
stackage2nix wrapper
You can use stackage2nix wrapper from nix
directory that adds required flags:
nix-env -i -f ./nix/stackage2nix
stackage2nix --with-stackage-closure ./stack.yaml
This command will produce packages.nix
and configuration-packages.nix
Stackage packages and its override in default.nix
Generate full Stackage
--with-stackage
parameter generates full Stackage LTS in addition to the
targets from stack.yaml
nix-env -i -f ./nix/stackage2nix
stackage2nix --with-stackage ./stack.yaml
Generate Stackage from LTS resolver
You can also generate only Stackage packages set from the resolver:
nix-env -i -f ./nix/stackage2nix
stackage2nix --resolver lts-10.0
This command will produce Stackage packages packages.nix
, packages config
configuration-packages.nix
and a Haskell packages set default.nix
.
Runtime dependencies
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
Override result derivation
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 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
Tests
Integration tests that build stackage2nix form different yaml configs:
STACKAGE_REPO=<path/to/stackage/repo> \
ALL_CABAL_HASHES=<path/to/all-cabal-hashes/repo> \
STACK_FILE=stack-ghc-7103.yaml \
./ci-stackage2nix