dhall: BREAKING CHANGE update dhall config for 1.33+ compatibility

Since dhall 1.33.0 lang version the `Optional/fold` function is
removed from the language and can be replaced by the usage of the
`merge` function which now works on Optional values 🎉 since 1.29

https://github.com/dhall-lang/dhall-haskell/pull/1608

This new code is thus not compatible with versions of dhall
<1.29.0 (due to the new feature of the `merge` fonction).

1 files changed, 22 insertions, 0 deletions

diff --git a/dhall-1.34.0.nix b/dhall-1.34.0.nix
new file mode 100644
index 0000000..a70d201
--- /dev/null
+++ b/dhall-1.34.0.nix
@@ -0,0 +1,22 @@
+{ pkgs ? import <nixpkgs> {} }: with pkgs;
+
+let
+  mkVersion =
+    version: sha256:
+      stdenv.mkDerivation {
+        name = "dhall-${version}";
+        inherit version;
+        src = fetchurl {
+          url = "https://github.com/dhall-lang/dhall-haskell/releases/download/${version}/dhall-${version}-x86_64-linux.tar.bz2";
+          inherit sha256;
+        };
+        unpackPhase = ''
+          tar -xjf $src
+        '';
+        installPhase = ''
+          mkdir -p $out/bin
+          mv bin/dhall $out/bin/
+        '';
+      };
+in
+  mkVersion "1.34.0" "0n64jkgbv7a3cmlv3gxpgc11p9b5w0k9nc0zm9am2pzmp6vm6b4n"