Unverified Commit 9a8850ae authored by Gabriella Gonzalez's avatar Gabriella Gonzalez Committed by GitHub
Browse files

dhallToNix: Permit inputs referring to derivations (#134459) 

Fixes https://github.com/dhall-lang/dhall-haskell/issues/2267

`pkgs.dhallToNix` currently fails when a Dhall package is
interpolated into the input source code, like this:

```nix
let
  pkgs = import <nixpkgs> { };

  f = { buildDhallPackage }: buildDhallPackage {
    name = "not";
    code = "λ(x : Bool) → x == False";
    source = true;
  };

  not = pkgs.dhallPackages.callPackage f {};

in
  pkgs.dhallToNix "${not}/source.dhall True"
```

This is because `dhallToNix` was using `builtins.toFile`, which
does not permit inputs with interpolated derivations.  However,
`pkgs.writeText` does not have this limitation, so we can switch
to using that instead.
parent 1c145df9

pkgs/build-support/dhall-to-nix.nix

+2 −2
Original line number Diff line number Diff line
@@ -15,12 +15,12 @@ 
    Note that this uses "import from derivation", meaning that Nix will perform

    a build during the evaluation phase if you use this `dhallToNix` utility

*/

{ stdenv, dhall-nix }:

{ stdenv, dhall-nix, writeText }:



let

  dhallToNix = code :

    let

      file = builtins.toFile "dhall-expression" code;

      file = writeText "dhall-expression" code;



      drv = stdenv.mkDerivation {

        name = "dhall-compiled.nix";