gentoo GK_SHARE is not set

emerge --info sys-kernel/genkernel

Portage 3.0.14 (python 3.8.7-final-0, default/linux/amd64/17.1/hardened, gcc-9.3.0, glibc-2.32-r7, 5.10.10-gentoo x86_64)
=================================================================
                         System Settings
=================================================================
System uname: Linux-5.10.10-gentoo-x86_64-Intel-R-_Core-TM-_i7-8750H_CPU_@_2.20GHz-with-glibc2.2.5
KiB Mem:    16234800 total,  15927352 free
KiB Swap:    4194300 total,   4194300 free
Timestamp of repository gentoo: Wed, 27 Jan 2021 00:45:01 +0000
Head commit of repository gentoo: f6dc00fd47701bf7b9891258ff4331fbe9f47abe
sh bash 5.1_p4
ld GNU ld (Gentoo 2.34 p6) 2.34.0
app-shells/bash:          5.1_p4::gentoo
dev-lang/perl:            5.32.0-r1::gentoo
dev-lang/python:          3.8.7-r1::gentoo, 3.9.1-r1::gentoo
dev-util/cmake:           3.19.3::gentoo
sys-apps/baselayout:      2.7-r1::gentoo
sys-apps/openrc:          0.42.1-r1::gentoo
sys-apps/sandbox:         2.20::gentoo
sys-devel/autoconf:       2.13-r1::gentoo, 2.69-r5::gentoo
sys-devel/automake:       1.16.3-r1::gentoo
sys-devel/binutils:       2.34-r2::gentoo, 2.35.1-r1::gentoo
sys-devel/gcc:            9.3.0-r2::gentoo, 10.2.0-r5::gentoo
sys-devel/gcc-config:     2.3.3::gentoo
sys-devel/libtool:        2.4.6-r6::gentoo
sys-devel/make:           4.3::gentoo
sys-kernel/linux-headers: 5.10::gentoo (virtual/os-headers)
sys-libs/glibc:           2.32-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-jobs: 1
    sync-rsync-extra-opts: 
    sync-rsync-verify-max-age: 24
    sync-rsync-verify-metamanifest: yes

ACCEPT_KEYWORDS="amd64 ~amd64"
ACCEPT_LICENSE="@FREE"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=native -O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/sandbox.d /etc/terminfo"
CXXFLAGS="-march=native -O2 -pipe"
DISTDIR="/var/cache/distfiles"
EMERGE_DEFAULT_OPTS="--jobs=12 --load-average=12"
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="-march=native -O2 -pipe"
FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs buildpkg cgroup collision-protect config-protect-if-modified distlocks downgrade-backup ebuild-locks fixlafiles ipc-sandbox merge-sync multilib-strict network-sandbox news parallel-fetch parallel-install pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms sign strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr"
FFLAGS="-march=native -O2 -pipe"
GENTOO_MIRRORS="https://gentoo-mirror.alexxy.name/ http://gentoo-mirror.alexxy.name/ http://gentoo.bloodhost.ru/ ftp://gentoo.bloodhost.ru/ rsync://gentoo.bloodhost.ru/gentoo-distfiles https://mirror.yandex.ru/gentoo-distfiles/ http://mirror.yandex.ru/gentoo-distfiles/ ftp://mirror.yandex.ru/gentoo-distfiles/"
LANG="ru_RU.utf8"
LDFLAGS="-Wl,-O1 -Wl,--as-needed"
MAKEOPTS="-j12 -l12"
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="acl alsa amd64 bzip2 crypt elogind hardened iconv ipv6 libglvnd libtirpc multilib ncurses nptl nvidia openmp pam pcre pie readline seccomp split-usr ssl ssp unicode xattr xtpax zlib" ABI_X86="64" ADA_TARGET="gnat_2018" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel 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="mmx mmxext sse sse2" 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="evdev libinput joystick wacom" 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="postgres10 postgres11" PYTHON_SINGLE_TARGET="python3_8" PYTHON_TARGETS="python2_7 python3_8" RUBY_TARGETS="ruby26" USERLAND="GNU" VIDEO_CARDS="amdgpu fbdev intel nouveau radeon radeonsi vesa dummy v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account"
Unset:  CC, CPPFLAGS, CTARGET, CXX, INSTALL_MASK, LC_ALL, LINGUAS, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

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                        Package Settings
=================================================================

sys-kernel/genkernel-4.1.2-r3::gentoo was built with the following:
USE="firmware (-ibm)" ABI_X86="(64)