젠투 포테지 업그레이드시 발생하는 문제..

아래와 같이 에러가 납니다.

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

sys-apps/portage:0

(sys-apps/portage-2.2.26:0/0::gentoo, ebuild scheduled for merge) pulled in by
sys-apps/portage (Argument)

(sys-apps/portage-2.2.14:0/0::gentoo, installed) pulled in by
sys-apps/portage[python_targets_python2_7(-)?,python_targets_python3_3(-)?,python_targets_python3_4(-)?,python_targets_pypy(-)?,-python_single_target_python2_7(-),-python_single_target_python3_3(-),-python_single_target_python3_4(-),-python_single_target_pypy(-)] required by (app-portage/gentoolkit-0.3.0.9-r2:0/0::gentoo, installed)

It may be possible to solve this problem by using package.mask to
prevent one of those packages from being selected. However, it is also
possible that conflicting dependencies exist such that they are
impossible to satisfy simultaneously. If such a conflict exists in
the dependencies of two different packages, then those packages can
not be installed simultaneously. You may want to try a larger value of
the --backtrack option, such as --backtrack=30, in order to see if
that will solve this conflict automatically.

For more information, see MASKED PACKAGES section in the emerge man
page or refer to the Gentoo Handbook.

멀티플 패키지 인스턴스는 언제부턴가 종종 보이던 녀석같은데

밑에 메세지는 첨 보네요..

원인이 뭔지 어떻게 해결해야하는지를 모르겠어요

언제부턴가 젠투가 점점 어려워졌어요

다른 배포판으로 갈아타야하나 하는 생각이 자꾸 듭니다.