$ emerge -p -uvDU @world

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

Calculating dependencies  ... ... .... done!
[ebuild     U  ] media-libs/libglvnd-1.3.4::gentoo [1.3.3::gentoo] USE="X -test" ABI_X86="32 (64) (-x32)" 0 KiB
[blocks B      ] >=media-libs/libglvnd-1.3.4 (">=media-libs/libglvnd-1.3.4" is blocking kde-plasma/kwin-5.22.4-r2)

Total: 1 package (1 upgrade), Size of downloads: 0 KiB
Conflict: 1 block (1 unsatisfied)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  (media-libs/libglvnd-1.3.4:0/0::gentoo, ebuild scheduled for merge) pulled in by
    >=media-libs/libglvnd-1.3.2[X?,abi_x86_32(-)?,abi_x86_64(-)?,abi_x86_x32(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?,abi_s390_32(-)?,abi_s390_64(-)?] (>=media-libs/libglvnd-1.3.2[X,abi_x86_32(-),abi_x86_64(-)]) required by (media-libs/mesa-21.2.1:0/0::gentoo, installed) USE="X classic egl gallium gbm gles2 llvm vaapi vdpau wayland zstd -d3d9 -debug -gles1 -lm-sensors -opencl -osmesa (-selinux) -test -unwind -valgrind -vulkan -vulkan-overlay -xa -xvmc -zink" ABI_X86="32 (64) (-x32)" VIDEO_CARDS="intel nouveau radeon radeonsi (-freedreno) -i915 -i965 -iris (-lima) (-panfrost) -r100 -r200 -r300 -r600 (-v3d) (-vc4) -virgl (-vivante) -vmware"
    media-libs/libglvnd[X] required by (x11-base/xorg-server-1.20.13-r1:0/1.20.13::gentoo, installed) USE="ipv6 systemd udev xorg xvfb -debug -dmx -doc (-elogind) -kdrive -minimal (-selinux) -suid -test -unwind -xcsecurity -xephyr -xnest" ABI_X86="(64)"
    media-libs/libglvnd[X] required by (net-misc/teamviewer-15.20.6:0/0::gentoo, installed) USE="" ABI_X86="(64)"
    media-libs/libglvnd required by (gui-libs/egl-wayland-1.1.7-r1:0/0::gentoo, installed) USE="" ABI_X86="(64)"
    media-libs/libglvnd[X,abi_x86_32(-)?,abi_x86_64(-)?,abi_x86_x32(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?,abi_s390_32(-)?,abi_s390_64(-)?] (media-libs/libglvnd[X,abi_x86_32(-),abi_x86_64(-)]) required by (x11-drivers/nvidia-drivers-470.63.01:0/470::gentoo, installed) USE="X dist-kernel driver tools wayland -static-libs" ABI_X86="32 (64) (-x32)"
    media-libs/libglvnd required by (x11-drivers/nvidia-drivers-470.63.01:0/470::gentoo, installed) USE="X dist-kernel driver tools wayland -static-libs" ABI_X86="32 (64) (-x32)"
    media-libs/libglvnd required by (dev-util/pycharm-community-2021.1.2-r1:0/0::gentoo, installed) USE="bundled-jdk" ABI_X86="(64)"
    media-libs/libglvnd[X] required by (x11-base/xwayland-21.1.2-r2:0/0::gentoo, installed) USE="ipv6 -rpc (-selinux) -unwind -xcsecurity" ABI_X86="(64)" VIDEO_CARDS="nvidia"
    media-libs/libglvnd[X] required by (app-emulation/virtualbox-6.1.26:0/6.1::gentoo, installed) USE="alsa opengl opus pam pulseaudio qt5 sdk udev -debug -doc -dtrace -headless -java -lvm -pax-kernel -python -vboxwebsrv -vnc" ABI_X86="(64)" PYTHON_SINGLE_TARGET="python3_9 -python3_8"

  (kde-plasma/kwin-5.22.4-r2:5/5::gentoo, installed) pulled in by
    >=kde-plasma/kwin-5.22.4:5 required by (kde-plasma/libkworkspace-5.22.4:5/5::gentoo, installed) USE="-debug -test" ABI_X86="(64)"
    >=kde-plasma/kwin-5.22.4:5 required by (kde-plasma/plasma-meta-5.22.4:5/5::gentoo, installed) USE="bluetooth browser-integration colord crash-handler crypt desktop-portal display-manager firewall gtk kwallet legacy-systray networkmanager pulseaudio sddm smart systemd wallpapers -accessibility -discover (-elogind) -grub -handbook -plymouth -qrcode -sdk -thunderbolt" ABI_X86="(64)"
    >=kde-plasma/kwin-5.22.4:5 required by (kde-plasma/plasma-desktop-5.22.4:5/5::gentoo, installed) USE="kaccounts policykit -debug -emoji -handbook -ibus -scim -semantic-desktop -test" ABI_X86="(64)"
    >=kde-plasma/kwin-5.22.4:5 required by (kde-plasma/plasma-workspace-5.22.4:5/5::gentoo, installed) USE="calculator calendar fontconfig screencast systemd -appstream -debug -geolocation -gps -handbook -semantic-desktop -telemetry -test" ABI_X86="(64)"


For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

https://wiki.gentoo.org/wiki/Handbook:X86/Working/Portage#Blocked_packages


 * IMPORTANT: 2 news items need reading for repository 'gentoo'.
 * Use eselect news read to view new items.


$ emerge --info
Portage 3.0.22 (python 3.9.6-final-0, !../../var/db/repos/kobboi-linux/profiles/kobboi/tanagra, gcc-11.2.0, glibc-2.33-r7, 5.13.13-gentoo-dist x86_64)
=================================================================
System uname: Linux-5.13.13-gentoo-dist-x86_64-AMD_Ryzen_9_5950X_16-Core_Processor-with-glibc2.33
KiB Mem:   131861848 total, 124597692 free
KiB Swap:          0 total,         0 free
Timestamp of repository gentoo: Mon, 30 Aug 2021 19:00:01 +0000
Head commit of repository gentoo: fa43bb89373142efc9f6289dbedba688f5c15e16
Timestamp of repository brother-overlay: Sun, 29 Aug 2021 23:06:55 +0000
Head commit of repository brother-overlay: 301476d0b3d05566961bcf563e9f5ac2bc0adb88

Head commit of repository kobboi-linux: fdb52b4523e8f36fbe055eb5e6a58d9e1c2e11df

Timestamp of repository steam-overlay: Mon, 30 Aug 2021 01:36:45 +0000
Head commit of repository steam-overlay: 31b40af28689e89c862f84d3c9c2a254ed9d2735

sh bash 5.1_p8
ld GNU ld (Gentoo 2.37_p1 p0) 2.37
distcc 3.4 x86_64-pc-linux-gnu [disabled]
ccache version 4.4 [disabled]
app-shells/bash:          5.1_p8::gentoo
dev-java/java-config:     2.3.1::gentoo
dev-lang/perl:            5.34.0-r2::gentoo
dev-lang/python:          2.7.18_p11::gentoo, 3.9.6_p1::gentoo, 3.10.0_rc1_p1::gentoo
dev-lang/rust:            1.54.0::gentoo
dev-util/ccache:          4.4::gentoo
dev-util/cmake:           3.21.2::gentoo
sys-apps/baselayout:      2.7-r3::gentoo
sys-apps/sandbox:         2.24::gentoo
sys-devel/autoconf:       2.13-r1::gentoo, 2.71-r1::gentoo
sys-devel/automake:       1.16.4::gentoo
sys-devel/binutils:       2.37_p1::gentoo
sys-devel/gcc:            11.2.0::gentoo
sys-devel/gcc-config:     2.4::gentoo
sys-devel/libtool:        2.4.6-r6::gentoo
sys-devel/make:           4.3::gentoo
sys-kernel/linux-headers: 5.13::gentoo (virtual/os-headers)
sys-libs/glibc:           2.33-r7::gentoo
Repositories:

gentoo
    location: /var/db/repos/gentoo
    sync-type: rsync
    sync-uri: rsync://rsync.gentoo.org/gentoo-portage
    priority: -1000
    sync-rsync-verify-max-age: 24
    sync-rsync-verify-jobs: 1
    sync-rsync-extra-opts: 
    sync-rsync-verify-metamanifest: yes

brother-overlay
    location: /var/db/repos/brother-overlay
    sync-type: git
    sync-uri: https://github.com/gentoo-mirror/brother-overlay.git
    masters: gentoo

kobboi-linux
    location: /var/db/repos/kobboi-linux
    sync-type: git
    sync-uri: https://github.com/kobboi/kobboi-linux
    masters: gentoo

steam-overlay
    location: /var/db/repos/steam-overlay
    sync-type: git
    sync-uri: https://github.com/gentoo-mirror/steam-overlay.git
    masters: gentoo

Installed sets: @kobboi-all-packages, @kobboi-machine-tanagra
ACCEPT_KEYWORDS="amd64 ~amd64"
ACCEPT_LICENSE="*"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-O2 -march=znver3 -pipe -g -ggdb"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /lib/modules /usr/share/config /usr/share/gnupg/qualified.txt /usr/share/maven-bin-3.8/conf"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php7.4/ext-active/ /etc/php/apache2-php8.0/ext-active/ /etc/php/cgi-php7.4/ext-active/ /etc/php/cgi-php8.0/ext-active/ /etc/php/cli-php7.4/ext-active/ /etc/php/cli-php8.0/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c"
CXXFLAGS="-O2 -march=znver3 -pipe -g -ggdb"
DISTDIR="/var/cache/distfiles"
ENV_UNSET="CARGO_HOME DBUS_SESSION_BUS_ADDRESS DISPLAY GOBIN GOPATH PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR"
FCFLAGS="-O2 -march=znver3 -pipe -g -ggdb"
FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs buildpkg compressdebug config-protect-if-modified distlocks ebuild-locks fixlafiles installsources ipc-sandbox merge-sync multilib-strict network-sandbox news parallel-install pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms splitdebug strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr"
FFLAGS="-O2 -march=znver3 -pipe -g -ggdb"
GENTOO_MIRRORS="ftp://kobboi-linux:*password*@10.8.0.1/2020.11"
INSTALL_MASK="/usr/src/debug /usr/lib/debug"
LANG="en_US.utf8"
LDFLAGS="-Wl,-O1 -Wl,--as-needed"
PKGDIR="/var/cache/binpkgs"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git"
PORTAGE_TMPDIR="/var/tmp"
USE="X a52 aac acl acpi alsa amd64 avahi bluetooth bzip2 cairo cdda cdr cli colord crypt cups dbus dist-kernel djvu dri dts dvd dvdr eds egl emboss encode evo exif facedetect ffmpeg flac fluidsynth fortran frei0r gdbm gif glade gles gles2 gnome gnome-keyring gnome-online-accounts gpm gstreamer gtk gtk3 gtkstyle gui iconv icu introspection ipv6 jpeg ladspa lcms libass libglvnd libnotify libsecret libtirpc lv2 lz4 lzma lzo mad midi mng modemmanager mono mp3 mp4 mpeg mtp multilib nautilus ncurses networkmanager nls nptl ogg opencv opengl openmp opus pam pango pcre pdf png policykit ppds pulseaudio qt5 readline samba screencast sdl seccomp smartcard smp spell split-usr ssl startup-notification svg sysprof systemd tcpd tiff truetype udev udisks unicode upower usb v4l vaapi vdpau vorbis wayland wxwidgets x264 xattr xcb xml xv xvid zeroconf zlib" ABI_X86="64" ADA_TARGET="gnat_2018" ALSA_CARDS="hda-intel ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx avx2 f16c fma3 mmx mmxext pclmul popcnt rdrand sha sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="keyboard mouse synaptics libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LUA_SINGLE_TARGET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php7-3 php7-4" POSTGRES_TARGETS="postgres12 postgres13" PYTHON_SINGLE_TARGET="python3_9" PYTHON_TARGETS="python3_9" RUBY_TARGETS="ruby26" USERLAND="GNU" VIDEO_CARDS="vesa radeon nvidia intel amdgpu dummy fbdev nouveau radeonsi v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq proto steal rawnat logmark ipmark dhcpmac delude chaos account"
Unset:  CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, LC_ALL, LINGUAS, MAKEOPTS, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, RUSTFLAGS