Add IGNORE_GIT_HASH.

CMakeLists.txt

@@ -110,6 +110,11 @@ OPTION( INJECT_DEBUG_POSTFIX
   ON
 )
 
+OPTION ( IGNORE_GIT_HASH
+   "Don't call git to get the hash."
+   OFF
+)
+
 IF (IOS)
   IF (NOT CMAKE_BUILD_TYPE)
     SET(CMAKE_BUILD_TYPE "Release")
@@ -153,23 +158,25 @@ SET( ASSIMP_PACKAGE_VERSION "0" CACHE STRING "the package-specific version used
 # Enable C++1 globally
 set_property( GLOBAL PROPERTY CXX_STANDARD 11 )
 
-# Get the current working branch
-EXECUTE_PROCESS(
-  COMMAND git rev-parse --abbrev-ref HEAD
-  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-  OUTPUT_VARIABLE GIT_BRANCH
-  OUTPUT_STRIP_TRAILING_WHITESPACE
-  ERROR_QUIET
-)
+IF(NOT IGNORE_GIT_HASH)
+  # Get the current working branch
+  EXECUTE_PROCESS(
+    COMMAND git rev-parse --abbrev-ref HEAD
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+    OUTPUT_VARIABLE GIT_BRANCH
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    ERROR_QUIET
+  )
 
-# Get the latest abbreviated commit hash of the working branch
-EXECUTE_PROCESS(
-  COMMAND git log -1 --format=%h --no-show-signature
-  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-  OUTPUT_VARIABLE GIT_COMMIT_HASH
-  OUTPUT_STRIP_TRAILING_WHITESPACE
-  ERROR_QUIET
-)
+  # Get the latest abbreviated commit hash of the working branch
+  EXECUTE_PROCESS(
+    COMMAND git log -1 --format=%h --no-show-signature
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+    OUTPUT_VARIABLE GIT_COMMIT_HASH
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    ERROR_QUIET
+  )
+ENDIF()
 
 IF(NOT GIT_COMMIT_HASH)
   SET(GIT_COMMIT_HASH 0)