From 2d34cee94202d11702881ddcd7bf80717f87f8c3 Mon Sep 17 00:00:00 2001
From: Alf Gaida <agaida@siduction.org>
Date: Sat, 10 Jan 2015 16:39:33 +0100
Subject: [PATCH] set GIT_HEAD and GIT_DESCRIBE from environment

---
 CMakeLists.txt | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f6e9f748..70b05c93 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -552,6 +552,17 @@ include(GetGitRevisionDescription)
 get_git_head_revision(GIT_REFSPEC GIT_HEAD)
 git_describe(GIT_DESCRIBE --long)
 
+# If not in a Git repo try to read GIT_HEAD and GIT_DESCRIBE from
+# enviroment
+if (NOT GIT_HEAD OR NOT GIT_DESCRIBE)
+  if (ENV_GIT_HEAD)
+      set(GIT_HEAD ${ENV_GIT_HEAD}) 
+  endif ()
+  if (ENV_GIT_DESCRIBE)
+     set(GIT_DESCRIBE ${ENV_GIT_DESCRIBE})
+  endif()
+endif()
+
 # Sanitize things if we're not in a Git repo
 if (NOT GIT_HEAD OR NOT GIT_DESCRIBE)
     set(GIT_HEAD "")
-- 
2.20.1