When there are unsatisfied conditional USE dependencies, emerge will report an unsatisfied dependency and suggest a USE change as follows emerge: there are no ebuilds built with USE flags to satisfy "dev-python/mock[python_targets_python2_7(-)?,python_targets_python3_3(-)?,python_targets_python3_4(-)?,python_targets_jython2_7(-) ?,-python_single_target_python2_7(-),-python_single_target_python3_3(-),-python_single_target_python3_4(-),-python_single_target_jython2_7(-)]". !!! One of the following packages is required to complete your request: - dev-python/foo::gentoo (Change USE: -python_targets_jython2_7) It would be nicer if emerge converted the "Change USE" suggestion into an autounmask change which can be automatically written to package.use when --autounmask-write is enabled.
There's a patch in the following branch: https://github.com/zmedico/portage/tree/bug_566704 I've posted it for review here: https://archives.gentoo.org/gentoo-portage-dev/message/fab681966acf99d7be6df55e5fa2054f
This is in the master branch: https://gitweb.gentoo.org/proj/portage.git/commit/?id=0c00530c92ecca3499c7d98fedae41a9ab559d17
Released in 2.2.26.
