/usr/lib/GNUstep/Applications/Poe.app/stamp.make is in poe.app 0.5.1-5build7.
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 = _NSApplication-Poe.tiff-Poe-