After adding python3_6 to PYTHON_TARGETS, dev-python/pycairo-1.16.3-r1 failed to build with USE=doc: [...] * python3_6: running distutils-r1_run_phase python_compile_all make -j5 -C docs make: Entering directory '/tmp/portage/dev-python/pycairo-1.16.3-r1/work/pycairo-1.16.3/docs' python -m sphinx -b html -n . _build /usr/bin/python3.6: No module named sphinx make: *** [Makefile:2: all] Error 1 make: Leaving directory '/tmp/portage/dev-python/pycairo-1.16.3-r1/work/pycairo-1.16.3/docs' * ERROR: dev-python/pycairo-1.16.3-r1::gentoo failed (compile phase): * emake failed Rebuilding dev-python/sphinx with the new PYTHON_TARGETS resolved the issue. This should be fixed in the ebuild however. The simple solution is to DEPEND on dev-python/sphinx[${PYTHON_USEDEP}] and be done with it. A solution that doesn't force all implemetations for sphinx would be more complex; something like this may work (not tested): DEPEND="doc? ( $(python_gen_any_dep 'dev-python/sphinx[${PYTHON_USEDEP}]') ) python_check_deps() { ! use doc || has_version "dev-python/sphinx[${PYTHON_USEDEP}]" }
Thank you for the report. Please recompile and *attach* the logfiles and paste the emerge info as described on https://wiki.gentoo.org/wiki/Attach_the_logs_to_the_bug_ticket Please reopen this ticket (Status:unconfirmed) afterwards.