这个 glibc 的 block 怎么搞？

主要还是看到 glibc 就害怕，不敢随便乱搞。。。

单独升级 glibc 的时候提示 slot 冲突。
!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:
dev-python/setuptools:0
(dev-python/setuptools-36.7.2:0/0::gentoo, ebuild scheduled for merge) pulled in by
dev-python/setuptools[python_targets_pypy(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/pyxattr-0.6.0-r1:0/0::gentoo, ebuild scheduled for merge)
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/certifi-2018.4.16:0/0::gentoo, ebuild scheduled for merge)
(dev-python/setuptools-36.7.2:0/0::gentoo, installed) pulled in by
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-)] required by (dev-python/cryptography-2.1.4-r1:0/0::gentoo, installed)
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/certifi-2018.4.16:0/0::gentoo, installed)
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/pygments-2.2.0:0/0::gentoo, installed)
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/traceback2-1.4.0:0/0::gentoo, installed)
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/unittest2-1.1.0:0/0::gentoo, installed)
dev-python/setuptools[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (dev-python/chardet-3.0.4:0/0::gentoo, installed)
dev-python/certifi:0
(dev-python/certifi-2018.4.16:0/0::gentoo, ebuild scheduled for merge) pulled in by
>=dev-python/certifi-2016.9.26[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-)] required by (dev-python/setuptools-36.7.2:0/0::gentoo, ebuild scheduled for merge)
(dev-python/certifi-2018.4.16:0/0::gentoo, installed) pulled in by
>=dev-python/certifi-2017.4.17[python_targets_python2_7(-),python_targets_python3_5(-),-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-)] required by (dev-python/requests-2.18.4:0/0::gentoo, installed)
dev-python/certifi[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-)] required by (dev-python/urllib3-1.22:0/0::gentoo, installed)
>=dev-python/certifi-2016.9.26[python_targets_pypy(-)?,python_targets_pypy3(-)?,python_targets_python2_7(-)?,python_targets_python3_4(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,-python_single_target_pypy(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_4(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-)] required by (dev-python/setuptools-36.7.2:0/0::gentoo, installed)

[nomerge ] sys-libs/glibc-2.26-r7:2.2::gentoo USE="(multilib) -audit -caps -debug -doc -gd (-hardened) -headers-only -nscd -profile (-selinux) -suid -systemtap (-vanilla)"
[ebuild U ] sys-libs/timezone-data-2018d::gentoo [2017c::gentoo] USE="nls -leaps_timezone" 568 KiB
Total: 166 packages (96 upgrades, 8 new, 4 in new slots, 58 reinstalls), Size of downloads: 703643 KiB
Conflict: 1 block
The following packages are causing rebuilds:
(app-text/mupdf-1.13.0:0/1.13.0::gentoo, ebuild scheduled for merge) causes rebuilds for:
(app-text/zathura-pdf-mupdf-0.3.2:0/0::gentoo, ebuild scheduled for merge)
(sys-libs/binutils-libs-2.30-r2:0/2.30::gentoo, ebuild scheduled for merge) causes rebuilds for:
(x11-libs/cairo-1.14.12:0/0::gentoo, ebuild scheduled for merge)
Would you like to merge these packages? [Yes/No]

很明显被这个阻止了，删除net-libs/libnsl 升级glibc在emerge 回net-libs/libnsl。

net-libs/libnsl-1.2.0
先升级libnsl库，如果有问题就先暂时 emerge -C掉它，再升级glibc
btw：长时间不升级，在升级前最好先做一次emerge -eavuDN @sYsTeM