35 lines
1.1 KiB
Nix
35 lines
1.1 KiB
Nix
# `dhallPackageToNix` is a utility function to take a Nixpkgs Dhall package
|
|
# (created with a function like `dhallPackages.buildDhallDirectoryPackage`)
|
|
# and read it in as a Nix expression.
|
|
#
|
|
# This function is similar to `dhallToNix`, but takes a Nixpkgs Dhall package
|
|
# as input instead of raw Dhall code.
|
|
#
|
|
# Note that this uses "import from derivation" (IFD), meaning that Nix will
|
|
# perform a build during the evaluation phase if you use this
|
|
# `dhallPackageToNix` utility. It is not possible to use `dhallPackageToNix`
|
|
# in Nixpkgs, since the Nixpkgs Hydra doesn't allow IFD.
|
|
|
|
{ stdenv, dhall-nix }:
|
|
|
|
dhallPackage:
|
|
let
|
|
drv = stdenv.mkDerivation {
|
|
name = "dhall-compiled-package.nix";
|
|
|
|
buildCommand = ''
|
|
# Dhall requires that the cache is writable, even if it is never written to.
|
|
# We copy the cache from the input package to the current directory and
|
|
# set the cache as writable.
|
|
cp -r "${dhallPackage}/.cache" ./
|
|
export XDG_CACHE_HOME=$PWD/.cache
|
|
chmod -R +w ./.cache
|
|
|
|
dhall-to-nix <<< "${dhallPackage}/binary.dhall" > $out
|
|
'';
|
|
|
|
nativeBuildInputs = [ dhall-nix ];
|
|
};
|
|
|
|
in import drv
|