Some time ago I've successfully installed Gentoo Linux on ARM64 development board. I had to use vendor-provided Linux kernel 4.4.38. Unfortunately, I had to downgrade linux-headers-4.13 to linux-headers-4.4 and rebuild glibc with this - I observed tons of invalid syscall messages in dmesg otherwise. Everything worked fine until this morning. A new feature KERNEL="(linux*)" appeared in today's portage update, along with mysterious, virtual/os-header dependency on linux-headers-4.13 which I masked in package.mask as such: >sys-kernel/linux-headers-4.4 Now I can't do any more updates as `emerge -uND world` shows this: The following mask changes are necessary to proceed: (see "package.unmask" in the portage(5) man page for more details) # required by virtual/os-headers-0::gentoo # required by sys-fs/udev-238::gentoo # required by @selected # required by @world (argument) # /etc/portage/package.mask: =sys-kernel/linux-headers-4.13 Note that udev-238 is happy with linux-headers 3.9 or greater. After all of this years of using Gentoo on different machines and architectures, I still can't find what exactly specifies this dependency on this particular version of linux-headers. Bumping EAPI for linux-headers-4.4 from 4 to 5 in local overlay didn't help. Reproducible: Always Portage 2.3.40 (python 2.7.14-final-0, default/linux/arm64/17.0/desktop, gcc-6.4.0, glibc-2.26-r7, 4.4.38-tegra aarch64) ================================================================= System uname: Linux-4.4.38-tegra-aarch64-with-gentoo-2.4.1 KiB Mem: 8039124 total, 6135368 free KiB Swap: 0 total, 0 free Timestamp of repository gentoo: Wed, 11 Jul 2018 04:15:01 +0000 Head commit of repository gentoo: 7ae7e27e486d46bc97fe496af06031f99bcaaaf3 sh bash 4.4_p12 ld GNU ld (Gentoo 2.29.1 p3) 2.29.1 app-shells/bash: 4.4_p12::gentoo dev-java/java-config: 2.2.0-r4::gentoo dev-lang/perl: 5.24.3-r1::gentoo dev-lang/python: 2.7.14-r1::gentoo, 3.5.5::gentoo, 3.6.5::gentoo dev-util/cmake: 3.9.6::gentoo dev-util/pkgconfig: 0.29.2::gentoo sys-apps/baselayout: 2.4.1-r2::gentoo sys-apps/openrc: 0.34.11::gentoo sys-apps/sandbox: 2.13::gentoo sys-devel/autoconf: 2.13::gentoo, 2.69-r4::gentoo sys-devel/automake: 1.11.6-r3::gentoo, 1.15.1-r2::gentoo sys-devel/binutils: 2.29.1-r1::gentoo, 2.30-r2::gentoo sys-devel/gcc: 6.4.0-r1::gentoo, 7.3.0-r3::gentoo sys-devel/gcc-config: 1.8-r1::gentoo sys-devel/libtool: 2.4.6-r3::gentoo sys-devel/make: 4.2.1::gentoo sys-kernel/linux-headers: 4.4::gentoo (virtual/os-headers) sys-libs/glibc: 2.26-r7::gentoo Repositories: gentoo location: /usr/portage sync-type: rsync sync-uri: rsync://rsync.uk.gentoo.org/gentoo-portage priority: -1000 sync-rsync-verify-jobs: 1 sync-rsync-verify-metamanifest: yes sync-rsync-extra-opts: -4 sync-rsync-verify-max-age: 24 jetson location: /usr/local/portage/overlay masters: gentoo priority: 0 ACCEPT_KEYWORDS="arm64" ACCEPT_LICENSE="* -@EULA" CBUILD="aarch64-unknown-linux-gnu" CFLAGS="-O2 -pipe -march=native -mcpu=cortex-a57 -mtune=cortex-a57" CHOST="aarch64-unknown-linux-gnu" CONFIG_PROTECT="/etc /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" CXXFLAGS="-O2 -pipe -march=native -mcpu=cortex-a57 -mtune=cortex-a57" DISTDIR="/usr/portage/distfiles" ENV_UNSET="DBUS_SESSION_BUS_ADDRESS DISPLAY 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" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync multilib-strict news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-O2" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j1" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_EXTRA_OPTS="-4" 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="7zip X Xaw3d a52 aac acl acpi alsa amrenc ao arm64 audiofile bat berkdb bluetooth bonjour boost branding bzip2 c++11 cacert cairo caps cdda cddb cdr chromaprint cli conntrack consolekit corefonts crypt cscope cups curl cxx dbus declarative djvu dri dri3 dts dvdr egl elfutils emboss encode equalizer evdev exif expat extras faac faad fam ffmpeg fft fftw flac fontconfig fontforge fortran ftp games gdbm gdk-pixbuf gif glamor gme gmp gold graphviz gsettings gsm gstreamer gtk guile hdf5 heterogeneous highlight hotkeys http hwloc iconv icu imagemagick int64 iproute2 ipv4 java javascript jbig jemalloc joystick jpeg jpeg2k json kdrive lame largepages lcms libatomic libdrm libffi libmpeg2 libnotify libsamplerate libsoxr libtirpc lldb lua lz4 lzma lzo mad md5sum minizip mng modules mp3 mp3rtp mp4 mpeg mpfi mpfr multilib multimedia ncurses neon netcdf nls nptl ntl numa ocr offensive ogg ompt openal opendx opengl openh264 openmp openpgp openssl opus osmesa pam pango paraview pcre pdf perl pgm phonon physfs plugins png pnm policykit postproc postscript ppds pulseaudio python qml qt5 rar readline rle romio seccomp secure-delete serialport smp smpeg sndfile sound sox soxr speex spell sqlite ssh ssl startup-notification suggested svg szip tahoma tcl tcpd theora tiff tk tools tremor truetype twolame udev udisks unicode unwind upower usb utils vaapi vnc vorbis wad wavpack wayland webkit webp widgets wxwidgets x11extras x264 x265 xattr xcb xephyr xft xinetd xml xmlpatterns xmp xnest xpm xv xvfb xvid yaml yuv4mpeg zeroconf zeromq zimg zlib" 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 plan sheets stage words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_ARM="neon edsp thumb thumb2 v4 v5 v6 v7 v8 vfp vfp-d32 vfpv3 vfpv4" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="evdev keyboard mouse joystick libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-6 php7-0" POSTGRES_TARGETS="postgres9_5 postgres10" PYTHON_SINGLE_TARGET="python3_6" PYTHON_TARGETS="python2_7 python3_6" RUBY_TARGETS="ruby21 ruby23" USERLAND="GNU" VIDEO_CARDS="tegra fbdev" 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, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, LINGUAS, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS
Trying to reinstall 'perf' gives simpler message: The following mask changes are necessary to proceed: (see "package.unmask" in the portage(5) man page for more details) # required by virtual/os-headers-0::gentoo # required by @system # required by @world (argument) # /etc/portage/package.mask: =sys-kernel/linux-headers-4.13
ok, perf turned out to be the reason for this. Downgraded it to perf-4.4.4 and now the problem is gone. Sorry for the disturbance caused.