'MAKEOPTS=-j1 emerge -v1 pycairo' fails with: ... * python3_6: running distutils-r1_run_phase python_compile_all make -j1 -C docs make: Entering directory '/var/tmp/portage/dev-python/pycairo-1.16.3-r1/work/pycairo-1.16.3/docs' python -m sphinx -b html -n . _build Traceback (most recent call last): File "/usr/lib64/python3.6/runpy.py", line 193, in _run_module_as_main "__main__", mod_spec) File "/usr/lib64/python3.6/runpy.py", line 85, in _run_code exec(code, run_globals) File "/usr/lib64/python3.6/site-packages/sphinx/__main__.py", line 16, in <module> sys.exit(main(sys.argv[1:])) File "/usr/lib64/python3.6/site-packages/sphinx/cmd/build.py", line 38, in main return build_main(argv) File "/usr/lib64/python3.6/site-packages/sphinx/cmd/build.py", line 22, in build_main from sphinx import cmdline File "/usr/lib64/python3.6/site-packages/sphinx/cmdline.py", line 24, in <module> from sphinx.application import Sphinx File "/usr/lib64/python3.6/site-packages/sphinx/application.py", line 30, in <module> from sphinx.config import Config File "/usr/lib64/python3.6/site-packages/sphinx/config.py", line 22, in <module> from sphinx.util.i18n import format_date File "/usr/lib64/python3.6/site-packages/sphinx/util/i18n.py", line 22, in <module> import babel.dates ModuleNotFoundError: No module named 'babel' make: *** [Makefile:2: all] Error 1 'USE=-doc MAKEOPTS=-j1 emerge -v1 pycairo' works.
Was a missing dep in Sphinx. Long ago fixed.