build: Generate "reproducible" version strings on "clean" builds

If the build environment looks "clean" then don't add the build
hostname or build time to the version string.  This makes the default
build string reproducible across builds.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

diff --git a/scripts/buildversion.py b/scripts/buildversion.py
index 56bfcfa4bc6dd4fa83d064543a5b407e77d67bd8..c3a83b015ed73189d73e731c8e6df5355a82d4e8 100755 (executable)
--- a/scripts/buildversion.py
+++ b/scripts/buildversion.py
@@ -92,14 +92,16 @@ def main():
     cleanbuild, toolstr = tool_versions(options.tools)
 
     ver = git_version()
+    cleanbuild = cleanbuild and ver and 'dirty' not in ver
     if not ver:
         ver = file_version()
         if not ver:
             ver = "?"
-    btime = time.strftime("%Y%m%d_%H%M%S")
-    hostname = socket.gethostname()
-    ver = "%s-%s-%s%s" % (ver, btime, hostname, options.extra)
-    write_version(outfile, ver, toolstr)
+    if not cleanbuild:
+        btime = time.strftime("%Y%m%d_%H%M%S")
+        hostname = socket.gethostname()
+        ver = "%s-%s-%s" % (ver, btime, hostname)
+    write_version(outfile, ver + options.extra, toolstr)
 
 if __name__ == '__main__':
     main()