midterm5 ~ # emerge -vauDNU @world

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

Calculating dependencies... done!

!!! All ebuilds that could satisfy "dev-lang/python:3.9" have been masked.
!!! One of the following masked packages is required to complete your request:
- dev-lang/python-3.9.1::liguros-repo (masked by: package.mask)

(dependency required by "dev-util/glib-utils-2.66.3::liguros-repo[python_single_target_python3_9]" [installed])
(dependency required by "media-libs/harfbuzz-2.7.2::liguros-repo[introspection]" [installed])
(dependency required by "dev-qt/qtgui-5.15.2::liguros-repo" [installed])
(dependency required by "dev-qt/qtwidgets-5.15.2::liguros-repo" [installed])
(dependency required by "dev-util/cmake-3.19.1-r1::liguros-repo[qt5]" [installed])
(dependency required by "dev-libs/libical-3.0.8::liguros-repo" [installed])
(dependency required by "net-wireless/bluez-5.55::liguros-repo" [installed])
(dependency required by "dev-lang/python-3.7.9-r1::liguros-repo[bluetooth]" [installed])
(dependency required by "x11-base/xcb-proto-1.14.1::liguros-repo[python_targets_python3_7]" [ebuild])
(dependency required by "x11-libs/xcb-util-cursor-0.1.3-r3::nokit" [installed])
(dependency required by "x11-libs/xcb-util-0.4.0-r2::nokit" [installed])
(dependency required by "x11-libs/xcb-util-image-0.4.0-r2::nokit" [installed])
For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.