Second issue I found. After install is completed, executing "root" at a command line gives a syntax error. Upstream documentation presumes this works; temporarily solved by symlinking /usr/lib/root/bin/root to /bin/root. There are several commands in /usr/lib/root/bin that probably ought to be on the path too. Here's my emerge --info, with the parts it identifies as links removed: Portage 3.0.28 (python 3.9.7-final-0, default/linux/amd64/17.1/hardened, gcc-11.2.0, glibc-2.33-r7, 5.14.1-gentoo x86_64) ================================================================= System uname: KiB Mem: 8076808 total, 4406684 free KiB Swap: 16777212 total, 16531220 free Timestamp of repository gentoo: Sat, 09 Oct 2021 20:30:02 +0000 Head commit of repository gentoo: 596c25ca0420cc0c5f22ffbdc6b9db8b0e3e78a3 Head commit of repository librewolf: 6fa10836bc2bbea21cdf986c51cede0b94355019 Head commit of repository slstatus: 84a2f117a32f0796045941260cdc4b69852b41e0 sh bash 5.1_p8 ld GNU ld (Gentoo 2.37_p1 p0) 2.37 app-shells/bash: 5.1_p8::gentoo dev-java/java-config: 2.3.1::gentoo dev-lang/perl: 5.34.0-r3::gentoo dev-lang/python: 3.9.7::gentoo, 3.10.0::gentoo dev-lang/rust: 1.55.0::gentoo dev-util/cmake: 3.21.3::gentoo sys-apps/baselayout: 2.8::gentoo sys-apps/openrc: 0.44.6::gentoo sys-apps/sandbox: 2.25::gentoo sys-devel/autoconf: 2.13-r1::gentoo, 2.71-r1::gentoo sys-devel/automake: 1.16.5::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: 5.14::gentoo (virtual/os-headers) sys-libs/glibc: 2.33-r7::gentoo Repositories: gentoo location: /var/db/repos/gentoo sync-type: rsync sync-uri: priority: -1000 sync-rsync-verify-metamanifest: yes sync-rsync-extra-opts: sync-rsync-verify-jobs: 1 sync-rsync-verify-max-age: 24 librewolf location: /var/db/repos/librewolf sync-type: git sync-uri: masters: gentoo slstatus location: /var/db/repos/slstatus sync-type: git sync-uri: masters: gentoo steam-overlay location: /var/lib/layman/steam-overlay masters: gentoo priority: 50 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/lib64/libreoffice/program/sofficerc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /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="-march=native -O2 -pipe" 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="-march=native -O2 -pipe" FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles ipc-sandbox merge-sync multilib-strict network-sandbox news parallel-fetch pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-march=native -O2 -pipe" GENTOO_MIRRORS="" LANG="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j4" 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 acl alsa amd64 bzip2 crypt dmenu elogind emacs hardened iconv ipv6 libglvnd libtirpc libxcrypt multilib ncurses nls nptl openmp pam pcre pie readline seccomp split-usr ssl ssp unicode xattr xtpax zlib zsh-completion" ABI_X86="64" ADA_TARGET="gnat_2019" 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="aes avx avx2 f16c fma3 mmx mmxext pclmul popcnt rdrand sse sse2 sse3 sse4_1 sse4_2 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" GRUB_PLATFORMS="efi-64" INPUT_DEVICES="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="nouveau" 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, INSTALL_MASK, LC_ALL, LINGUAS, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, RUSTFLAGS
The other bug is not related to this one. The ebuild does put the commands in the PATH, but uses env.d for that, like llvm. This is to allow you to have more than one version of ROOT installed in the same system. If you just start a new shell after emerging ROOT, you should see that it's in the PATH.