1 files changed, 19 insertions, 0 deletions
diff --git a/third_party/overlays/haskell/default.nix b/third_party/overlays/haskell/default.nix
new file mode 100644
index 0000000000..8ea57f2096
--- /dev/null
+++ b/third_party/overlays/haskell/default.nix
@@ -0,0 +1,19 @@
+# Defines an overlay for overriding Haskell packages, for example to
+# avoid breakage currently present in nixpkgs or to modify package
+# versions.
+
+{ lib, ... }:
+
+self: super: # overlay parameters for the nixpkgs overlay
+
+let
+  overrides = hsSelf: hsSuper: with super.haskell.lib; {
+    generic-arbitrary = appendPatch hsSuper.generic-arbitrary
+      [ ./patches/generic-arbitrary-export-garbitrary.patch ];
+  };
+in
+{
+  haskellPackages = super.haskellPackages.override {
+    inherit overrides;
+  };
+}