In Slackware 14.1 and older, gzip does not support the --rsyncable option.
The compilation errors out as a result. So we remove the 'rsyncable' flag.

diff --git a/tools/grit/grit/format/gzip_string.py b/tools/grit/grit/format/gzip_string.py
index 4f54aac..68f9ea1 100644
--- a/tools/grit/grit/format/gzip_string.py
+++ b/tools/grit/grit/format/gzip_string.py
@@ -15,7 +15,7 @@ def GzipStringRsyncable(data):
   # Instead, --rsyncable breaks the file into small chunks, so that one doesn't
   # affect the other in compression, and then only that chunk will have to be
   # updated.
-  gzip_proc = subprocess.Popen(['gzip', '--stdout', '--rsyncable',
+  gzip_proc = subprocess.Popen(['gzip', '--stdout',
                                 '--best', '--no-name'],
                                stdin=subprocess.PIPE,
                                stdout=subprocess.PIPE,
-- 
2.7.4