From 53ddf53f2ca436f85ed022baba8812b9bf37d813 Mon Sep 17 00:00:00 2001
From: Luke Granger-Brown <git@lukegb.com>
Date: Mon, 3 May 2021 18:59:14 +0000
Subject: [PATCH] mercurial: add re2

Mercurial can make use of the RE2 regex engine where available to speed
up evaluation of regexes.
---
 pkgs/applications/version-management/mercurial/default.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pkgs/applications/version-management/mercurial/default.nix b/pkgs/applications/version-management/mercurial/default.nix
index 5a0469b36c4..4623765bd32 100644
--- a/pkgs/applications/version-management/mercurial/default.nix
+++ b/pkgs/applications/version-management/mercurial/default.nix
@@ -5,7 +5,7 @@
 }:
 
 let
-  inherit (python3Packages) docutils python;
+  inherit (python3Packages) docutils python fb-re2;
 
 in python3Packages.buildPythonApplication rec {
   pname = "mercurial";
@@ -28,6 +28,7 @@ in python3Packages.buildPythonApplication rec {
   } else null;
   cargoRoot = if rustSupport then "rust" else null;
 
+  propagatedBuildInputs = [ fb-re2 ];
   nativeBuildInputs = [ makeWrapper gettext ]
     ++ lib.optionals rustSupport (with rustPlatform; [
          cargoSetupHook