net-libs/webkit-gtk-2.28.4 builds successfully using python3.8 on ~amd64. Please add "python3_8" to PYTHON_COMPAT in the ebuild.
Does Python 3.9 work?
(In reply to Sam James from comment #1)
> Does Python 3.9 work?
I don't know. I haven't installed it yet, as my system has many packages that haven't yet declared compatibility with it.