/usr/lib/GNUstep/SaxDrivers-4.9/libxmlSAXDriver.sax/stamp.make is in libsope1 3.2.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1
OLD_GNUSTEP_STAMP_ASTRING = _libxmlSAXDriver-