From 5a43eec0704503f4b415814557ad22490a6165c1 Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Tue, 10 Oct 2017 23:06:45 -0400
Subject: [PATCH] nixpkgs: expose .git-revision in the nixexprs like NixOS

nixos/lib/make-channel.nix:16:

    echo -n ${nixpkgs.rev or nixpkgs.shortRev} > .git-revision

This means the .git-revision exists in nixos channels, but not
Nixpkgs channels. Adding it to the nixpkgs channel makes it a
common API for any Nixpkgs use cases.
---
 pkgs/top-level/make-tarball.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/top-level/make-tarball.nix b/pkgs/top-level/make-tarball.nix
index c7e5f21910b..16940761e6d 100644
--- a/pkgs/top-level/make-tarball.nix
+++ b/pkgs/top-level/make-tarball.nix
@@ -24,7 +24,9 @@ releaseTools.sourceTarball rec {
     eval "$preConfigure"
     releaseName=nixpkgs-$VERSION$VERSION_SUFFIX
     echo -n $VERSION_SUFFIX > .version-suffix
+    echo -n ${nixpkgs.rev or nixpkgs.shortRev} > .git-revision
     echo "release name is $releaseName"
+    echo "git-revision is $(cat .git-revision)"
   '';
 
   dontBuild = false;