pietro@raspberrypi ~ $ sudo emerge -auDN @world

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild   R    ] sys-apps/file-5.32  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] sys-libs/cracklib-2.9.6-r1  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-libs/libnl-3.2.28  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/six-1.10.0  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/appdirs-1.4.3  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/pyparsing-2.2.0  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/packaging-16.8  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/setuptools-34.0.2-r1  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/pygments-2.1.1  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/certifi-2017.4.17  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/pyxattr-0.5.5  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] sys-apps/portage-2.3.6  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-python/docutils-0.13.1  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] app-portage/gentoolkit-0.3.3  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] app-editors/vim-8.0.0386  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] sys-apps/util-linux-2.28.2  PYTHON_SINGLE_TARGET="-python3_4*" PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] dev-libs/libxml2-2.9.4-r1  PYTHON_TARGETS="-python3_4*"
[ebuild   R    ] sys-apps/kmod-23  PYTHON_TARGETS="-python3_4*"

Would you like to merge these packages? [Yes/No]