Here's a simple error in ete4 v4.4.0:
import ete4
ete4.Tree("(A);", parser=3)
resulting in
python3.12/site-packages/ete4/parser/newick.pyx:239, in ete4.parser.newick.read_props()
UnboundLocalError: local variable 'p1_str' referenced before assignment
I don't understand the code well enough to suggest a fix but am happy to send a pull request if someone tells me what to do :-)