I'm not sure if this is a recent dependency, but without this patch "import html5lib" complains about not finding webencodings module.
Marius Bakke (2): gnu: Add python-webencodings. gnu: python-html5lib: Add dependency on python-webencodings. gnu/packages/python.scm | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) -- 2.11.0