Add git SHA to information reported in SystemInformation test

CMake/VTKmSystemInformation.cmake

@@ -25,7 +25,7 @@
#
# This script is called with a command like:
#
-# cmake -D VTKm_BINARY_DIR=<top-of-build-tree> -P <this-script>
+# cmake -D VTKm_BINARY_DIR=<top-of-build-tree> -D VTKm_SOURCE_DIR=<top-of-source-tree> -P <this-script>
#
set(FILES
@@ -50,8 +50,21 @@ Contents of \"${filename}\":
endif()
endfunction(print_file)
+
message("CTEST_FULL_OUTPUT (Avoid ctest truncation of output)")
+execute_process(
+  COMMAND git rev-parse -q HEAD
+  WORKING_DIRECTORY "${VTKm_SOURCE_DIR}"
+  OUTPUT_VARIABLE GIT_SHA
+  )
+
+message("
+
+==============================================================================
+
+git SHA: ${GIT_SHA}")
+
foreach(filename ${FILES})
print_file(${filename})
endforeach()