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

Calculating dependencies |

!!! Problem resolving dependencies for sys-apps/util-linux from @system ... done!

!!! The ebuild selected to satisfy "sys-apps/util-linux" has unmet requirements.
- sys-apps/util-linux-2.29.2-r1::core-kit USE="cramfs ncurses nls pam python readline static-libs suid unicode -build -caps -fdformat -kill (-selinux) -slang (-systemd) -test -tty-helpers (-udev)" ABI_X86="32 (64) (-x32)" PYTHON_SINGLE_TARGET="-python2_7 -python3_4 -python3_5" PYTHON_TARGETS="-python2_7 -python3_4 -python3_5"

The following REQUIRED_USE flag constraints are unsatisfied:
python? ( exactly-one-of ( python_single_target_python2_7 python_single_target_python3_4 python_single_target_python3_5 ) )

The above constraints are a subset of the following complete expression:
python? ( exactly-one-of ( python_single_target_python2_7 python_single_target_python3_4 python_single_target_python3_5 ) python_single_target_python2_7? ( python_targets_python2_7 ) python_single_target_python3_4? ( python_targets_python3_4 ) python_single_target_python3_5? ( python_targets_python3_5 ) )

(dependency required by "@system" [set])
(dependency required by "@world" [argument])