it looks like this option is required to fix bug #592294 Thanks emerge --info Portage 2.2.28 (python 2.7.10-final-0, hardened/linux/amd64, gcc-4.9.3, glibc-2.22-r4, 4.4.8-pentoo-r1 x86_64) ================================================================= System uname: Linux-4.4.8-pentoo-r1-x86_64-Intel-R-_Core-TM-_i5-3320M_CPU_@_2.60GHz-with-gentoo-2.2 KiB Mem: 7981336 total, 3440956 free KiB Swap: 4194300 total, 4181196 free Timestamp of repository gentoo: Sat, 27 Aug 2016 07:30:01 +0000 sh bash 4.3_p42-r1 ld GNU ld (Gentoo 2.25.1 p1.1) 2.25.1 app-shells/bash: 4.3_p42-r1::gentoo dev-java/java-config: 2.2.0-r3::gentoo dev-lang/perl: 5.20.2::gentoo dev-lang/python: 2.7.10-r1::gentoo, 3.4.3-r1::gentoo dev-util/cmake: 3.5.2-r1::gentoo dev-util/pkgconfig: 0.28-r2::gentoo sys-apps/baselayout: 2.2::gentoo sys-apps/openrc: 0.21.3::gentoo sys-apps/sandbox: 2.10-r1::gentoo sys-devel/autoconf: 2.13::gentoo, 2.69::gentoo sys-devel/automake: 1.14.1::gentoo, 1.15::gentoo sys-devel/binutils: 2.25.1-r1::gentoo sys-devel/gcc: 4.9.3::gentoo sys-devel/gcc-config: 1.7.3::gentoo sys-devel/libtool: 2.4.6::gentoo sys-devel/make: 4.1-r1::gentoo sys-kernel/linux-headers: 4.3::gentoo (virtual/os-headers) sys-libs/glibc: 2.22-r4::gentoo Repositories: gentoo location: /usr/portage sync-type: rsync sync-uri: rsync://rsync.gentoo.org/gentoo-portage priority: -1000 steam-overlay location: /var/lib/layman/steam-overlay masters: gentoo priority: 0 pentoo location: /var/lib/layman/pentoo masters: gentoo priority: 1 local-overlay location: /usr/local/portage masters: gentoo priority: 2 ABI="amd64" ABI_X86="64" ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA OPERA-12 NVIDIA-CUDA PUEL AdobeFlash-11.x Google-TOS dlj-1.1 google-chrome Oracle-BCLA-JavaSE Intel-SDP skype-4.0.0.7-copyright baudline" ACCEPT_PROPERTIES="*" ACCEPT_RESTRICT="*" 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" ANDROID_HOME="/opt/android-sdk-update-manager" ANDROID_SWT="/usr/share/swt-3.7/lib" ANT_HOME="/usr/share/ant" 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" ARCH="amd64" AUTOCLEAN="yes" BOOTSTRAP_USE="cxx unicode internal-glib python_targets_python3_4 python_targets_python2_7 multilib hardened pax_kernel pic xtpax -jit -orc" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -pipe" CFLAGS_amd64="-m64" CFLAGS_x32="-mx32" CFLAGS_x86="-m32" CHOST="x86_64-pc-linux-gnu" CHOST_amd64="x86_64-pc-linux-gnu" CHOST_x32="x86_64-pc-linux-gnux32" CHOST_x86="i686-pc-linux-gnu" CLEAN_DELAY="5" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" COLLISION_IGNORE="/lib/modules/* *.py[co] *$py.class */dropin.cache" COLORFGBG="15;0" CONFIG_PROTECT="/etc /etc/stunnel/stunnel.conf /opt/sonar/conf /usr/share/config /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" CPU_FLAGS_X86="aes avx mmx mmxext popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3" CXXFLAGS="-march=native -O2 -pipe" DBUS_SESSION_BUS_ADDRESS="unix:abstract=/tmp/dbus-tpjQcLNzNN,guid=d4cf145d86b692282785188b57c140dc" DEFAULT_ABI="amd64" DESKTOP_SESSION="/usr/share/xsessions/plasma" DISPLAY=":0" DISTDIR="/usr/portage/distfiles" EDITOR="/usr/bin/mcedit" ELIBC="glibc" EMERGE_DEFAULT_OPTS=" --ask-enter-invalid --keep-going=y --binpkg-respect-use=y --tree --verbose --with-bdeps=y --autounmask=n --buildpkg-exclude "sys-kernel/compat-drivers sys-kernel/ax88179_178a x11-drivers/ati-drivers x11-drivers/nvidia-drivers sys-fs/zfs-kmod sys-kernel/spl sys-power/bbswitch pentoo/pentoo-installer x11-drivers/xf86-video-virtualbox app-emulation/virtualbox-guest-additions app-emulation/virtualbox-modules app-emulation/vmware-modules app-emulation/open-vm-tools-kmod sys-kernel/genkernel sys-kernel/pentoo-sources dev-python/twisted-web net-analyzer/metasploit sci-libs/lapack-reference x11-base/xorg-drivers app-admin/genmenu" --usepkg-exclude "sys-kernel/compat-drivers sys-kernel/ax88179_178a x11-drivers/ati-drivers x11-drivers/nvidia-drivers sys-fs/zfs-kmod sys-kernel/spl sys-power/bbswitch pentoo/pentoo-installer x11-drivers/xf86-video-virtualbox app-emulation/virtualbox-guest-additions app-emulation/virtualbox-modules app-emulation/vmware-modules app-emulation/open-vm-tools-kmod sys-kernel/genkernel sys-kernel/pentoo-sources dev-python/twisted-web net-analyzer/metasploit sci-libs/lapack-reference x11-base/xorg-drivers app-admin/genmenu"" EMERGE_WARNING_DELAY="10" EPREFIX="" EROOT="/" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FETCHCOMMAND="wget -t 3 -T 60 --passive-ftp -O "${DISTDIR}/${FILE}" "${URI}"" FETCHCOMMAND_RSYNC="rsync -avP "${URI}" "${DISTDIR}/${FILE}"" FETCHCOMMAND_SFTP="bash -c "x=\${2#sftp://} ; host=\${x%%/*} ; port=\${host##*:} ; host=\${host%:*} ; [[ \${host} = \${port} ]] && port=22 ; eval \"declare -a ssh_opts=(\${3})\" ; exec sftp -P \${port} \"\${ssh_opts[@]}\" \"\${host}:/\${x#*/}\" \"\$1\"" sftp "${DISTDIR}/${FILE}" "${URI}" "${PORTAGE_SSH_OPTS}"" FETCHCOMMAND_SSH="bash -c "x=\${2#ssh://} ; host=\${x%%/*} ; port=\${host##*:} ; host=\${host%:*} ; [[ \${host} = \${port} ]] && port=22 ; exec rsync --rsh=\"ssh -p\${port} \${3}\" -avP \"\${host}:/\${x#*/}\" \"\$1\"" rsync "${DISTDIR}/${FILE}" "${URI}" "${PORTAGE_SSH_OPTS}"" FFLAGS="-O2 -pipe" FLTK_DOCDIR="/usr/share/doc/fltk-1.3.3-r3/html" GCC_SPECS="" GENTOO_MIRRORS="http://gentoo.gg3.net"
This would be nice to have, but it not actually required for systemd if the user has /etc/mtab set up as a symlink to /proc/self/mounts.
It looks like this will be the default configuration in a future util-linux release. https://git.kernel.org/cgit/utils/util-linux/util-linux.git/commit/?id=e778642a9eb96975fcf3baa61dfa10add628af1a
