Hello,
I can confirm this bug. I'm using pygccxml at work - on buster, it issues a python warning that time.clock() is deprecated. On bullseye, the package does not work at all any more.
It seems pygccxml has been updated, there is a version 2.2.1 available. Either the python3-pygccxml
could be upgraded, or a python3-pygccxml2 package could be created?