...
Making install in docs/reference/gck
gmake[4]: Entering directory '/tmp/ports/usr/ports/security/gcr/work/gcr-3.28.0/docs/reference/gck'
gmake[5]: Entering directory '/tmp/ports/usr/ports/security/gcr/work/gcr-3.28.0/docs/reference/gck'
gmake[5]: Nothing to be done for 'install-exec-am'.
 install  -m 0644 ./html/annotation-glossary.html
...
 install  -m 0644 ./html/up-insensitive.png
 install  -m 0644 ./html/up.png
Traceback (most recent call last):
  File "/usr/local/bin/gtkdoc-rebase", line 56, in <module>
    sys.exit(rebase.run(options))
  File "/usr/local/share/gtk-doc/python/gtkdoc/rebase.py", line 75, in run
    ScanDirectory(dir, options)
  File "/usr/local/share/gtk-doc/python/gtkdoc/rebase.py", line 133, in ScanDirectory
    ScanDirectory(subdir, options)
  File "/usr/local/share/gtk-doc/python/gtkdoc/rebase.py", line 114, in ScanDirectory
    onlinedir = ReadIndex(dir, entry)
  File "/usr/local/share/gtk-doc/python/gtkdoc/rebase.py", line 153, in ReadIndex
    for line in common.open_text(os.path.join(dir, file)):
  File "/usr/local/lib/python3.6/posixpath.py", line 80, in join
    a = os.fspath(a)
TypeError: expected str, bytes or os.PathLike object, not builtin_function_or_method
gmake[5]: *** [Makefile:883: install-data-local] Error 1
gmake[5]: Leaving directory '/tmp/ports/usr/ports/security/gcr/work/gcr-3.28.0/docs/reference/gck'
gmake[4]: *** [Makefile:626: install-am] Error 2
...