diff --git a/third_party/nixpkgs/patches/pr163678.patch b/third_party/nixpkgs/patches/pr163678.patch
new file mode 100644
index 0000000000..662097c942
--- /dev/null
+++ b/third_party/nixpkgs/patches/pr163678.patch
@@ -0,0 +1,24 @@
+From f491e8c3326f102c0ef45f6b0abe0868d6df5bbd Mon Sep 17 00:00:00 2001
+From: Luke Granger-Brown <git@lukegb.com>
+Date: Fri, 11 Mar 2022 15:42:05 +0000
+Subject: [PATCH] mercurial: disable all non-essential phases in withExtensions
+
+---
+ pkgs/applications/version-management/mercurial/default.nix | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/pkgs/applications/version-management/mercurial/default.nix b/pkgs/applications/version-management/mercurial/default.nix
+index 17d21f30e3b24..0124cf0646e5e 100644
+--- a/pkgs/applications/version-management/mercurial/default.nix
++++ b/pkgs/applications/version-management/mercurial/default.nix
+@@ -181,6 +181,10 @@ in
+         nativeBuildInputs = self.nativeBuildInputs;
+ 
+         dontUnpack = true;
++        dontPatch = true;
++        dontConfigure = true;
++        dontBuild = true;
++        doCheck = false;
+ 
+         installPhase = ''
+           runHook preInstall
diff --git a/third_party/nixpkgs/patches/series b/third_party/nixpkgs/patches/series
index f5c44a2f9f..98374df6c6 100644
--- a/third_party/nixpkgs/patches/series
+++ b/third_party/nixpkgs/patches/series
@@ -1,2 +1,3 @@
 nvidia-sideband-socket.patch
 pr163673.patch
+pr163678.patch
diff --git a/third_party/nixpkgs/pkgs/applications/version-management/mercurial/default.nix b/third_party/nixpkgs/pkgs/applications/version-management/mercurial/default.nix
index 17d21f30e3..0124cf0646 100644
--- a/third_party/nixpkgs/pkgs/applications/version-management/mercurial/default.nix
+++ b/third_party/nixpkgs/pkgs/applications/version-management/mercurial/default.nix
@@ -181,6 +181,10 @@ in
         nativeBuildInputs = self.nativeBuildInputs;
 
         dontUnpack = true;
+        dontPatch = true;
+        dontConfigure = true;
+        dontBuild = true;
+        doCheck = false;
 
         installPhase = ''
           runHook preInstall