As python 3.6 is the default python compiler as of 2018-06-22 this package cannot install anymore. The error: !!! The ebuild selected to satisfy "sys-fs/bcache-tools" has unmet requirements. - sys-fs/bcache-tools-1.0.8_p20140220-r1::gentoo USE="" ABI_X86="(64)" PYTHON_TARGETS="-python3_4 -python3_5" The following REQUIRED_USE flag constraints are unsatisfied: any-of ( python_targets_python3_4 python_targets_python3_5 ) For workaround you can enable python 3.5 in make.conf but I simply changed the ebuild and it seems to work fine: -PYTHON_COMPAT=( python3_{4,5} ) +PYTHON_COMPAT=( python3_{4,5,6} ) This might be relevant: https://bugs.funtoo.org/browse/FL-4427
*** This bug has been marked as a duplicate of bug 658788 ***