doc build error: 'Sphinx' object has no attribute 'add_stylesheet'

[CarlFK]

carl@x1:~/src/fomu/fomu-workshop/docs$ make html 
Running Sphinx v7.2.6
fatal: No names found, cannot describe anything.

Extension error (sphinxcontrib_session):
Handler <function add_stylesheet at 0x7f46d03fca40> for event 'builder-inited' threw an exception (exception: 'Sphinx' object has no attribute 'add_stylesheet')
make: *** [Makefile:46: html] Error 2

[mithro]

Should be fixed by https://github.com/SymbiFlow/sphinxcontrib-session/pull/5 and https://github.com/mithro/sphinxcontrib-session/commit/84e4245d01ede6aa8cd4ac3a4d49866d7f9bb3eb