After updating to =sys-devel/gcc-4.8.3 tar begin to fail with tar: Skipping to next header tar: Exiting with failure status due to previous errors tar failed with status 2 Reproducible: Always Steps to Reproduce: 1. emerge =sys-devel/gcc-4.8.3 2. emerge =app-arch/tar-1.27.1-r2 3. emerge =sys-apps/kbd-1.15.5-r1 OR FEATURES="test" emerge =sys-apps/portage-2.2.8-r2
Portage 2.2.8-r2 (default/linux/amd64/13.0, gcc-4.8.3, glibc-2.19-r1, 3.16.0-pf1 x86_64) ================================================================= System uname: Linux-3.16.0-pf1-x86_64-Intel-R-_Core-TM-_i7-4600M_CPU_@_2.90GHz-with-gentoo-2.2 KiB Mem: 8051852 total, 3919640 free KiB Swap: 8388604 total, 8388604 free Timestamp of tree: Sun, 26 Oct 2014 08:15:02 +0000 ld GNU ld (Gentoo 2.23.2 p1.0) 2.23.2 app-shells/bash: 4.2_p53 dev-java/java-config: 2.2.0 dev-lang/perl: 5.18.2-r2 dev-lang/python: 2.7.7, 3.3.5-r1, 3.4.1 dev-util/cmake: 2.8.12.2-r1 dev-util/pkgconfig: 0.28-r1 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.12.4 sys-apps/sandbox: 2.6-r1 sys-devel/autoconf: 2.13, 2.69 sys-devel/automake: 1.11.6, 1.12.6, 1.13.4 sys-devel/binutils: 2.23.2 sys-devel/gcc: 4.8.3 sys-devel/gcc-config: 1.7.3 sys-devel/libtool: 2.4.2-r1 sys-devel/make: 4.0-r1 sys-kernel/linux-headers: 3.16 (virtual/os-headers) sys-libs/glibc: 2.19-r1 Repositories: gentoo science ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA Oracle-BCLA-JavaSE PUEL skype-4.0.0.7-copyright AdobeFlash-11.x" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O3 -pipe -march=native -mtune=corei7-avx" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt /usr/share/maven-bin-3.0/conf /var/lib/hsqldb" 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="-O3 -pipe -march=native -mtune=corei7-avx" DISTDIR="/usr/portage-distfiles" 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 test unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://mirror.yandex.ru/gentoo-distfiles/ http://trumpetti.atm.tut.fi/gentoo/ http://mirror.mdfnet.se/gentoo" LANG="ru_RU.utf8" LDFLAGS="-Wl,--as-needed -Wl,-O1 -Wl,--hash-style=gnu -O3 -pipe -march=native -mtune=corei7-avx" MAKEOPTS="-j4" PKGDIR="/usr/portage-packages" 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" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/var/lib/layman/science" SYNC="rsync://rsync2.ru.gentoo.org/gentoo-portage" USE="X acl alsa amd64 avx avx2 berkdb bzip2 cairo cli cracklib crypt cups cxx dbus djvu dri flac fortran gdbm iconv icu idn ipv6 jpeg lzma lzo mmx modules multilib ncurses nls nptl opengl openmp pam pcre png policykit pulseaudio python readline session smp sse sse2 sse3 sse4 sse4_1 ssl ssse3 svg tcpd truetype unicode usb xcb xft xml zlib" ABI_X86="64" 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="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" GRUB_PLATFORMS="pc efi-64" INPUT_DEVICES="evdev keyboard mouse synaptics" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="ru en" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-5" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_3" RUBY_TARGETS="ruby20" USERLAND="GNU" VIDEO_CARDS="intel i915 i965 nouveau nvidia" 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: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON
=sys-apps/kbd-1.15.5-r1 build.log * Package: sys-apps/kbd-1.15.5-r1 * Repository: gentoo * Maintainer: base-system@gentoo.org * USE: abi_x86_64 amd64 elibc_glibc kernel_linux nls pam test userland_GNU * FEATURES: preserve-libs sandbox test userpriv usersandbox >>> Unpacking source... >>> Unpacking kbd-1.15.5.tar.gz to /var/tmp/portage/sys-apps/kbd-1.15.5-r1/work tar: Skipping to next header tar: Exiting with failure status due to previous errors * ERROR: sys-apps/kbd-1.15.5-r1::gentoo failed (unpack phase): * failure unpacking kbd-1.15.5.tar.gz * * Call stack: * ebuild.sh, line 93: Called src_unpack * environment, line 1900: Called default * phase-functions.sh, line 796: Called __eapi2_src_unpack * phase-functions.sh, line 787: Called __eapi0_src_unpack * phase-helpers.sh, line 648: Called unpack 'kbd-1.15.5.tar.gz' * phase-helpers.sh, line 357: Called __unpack_tar 'gzip -d' * phase-helpers.sh, line 299: Called __assert_sigpipe_ok 'failure unpacking kbd-1.15.5.tar.gz' * isolated-functions.sh, line 39: Called die * The specific snippet of code: * [[ $x -ne 0 && $x -ne ${PORTAGE_SIGPIPE_STATUS:-141} ]] && die "$@" * * If you need support, post the output of `emerge --info '=sys-apps/kbd-1.15.5-r1::gentoo'`, * the complete build log and the output of `emerge -pqv '=sys-apps/kbd-1.15.5-r1::gentoo'`. * The complete build log is located at '/var/tmp/portage/sys-apps/kbd-1.15.5-r1/temp/build.log'. * The ebuild environment file is located at '/var/tmp/portage/sys-apps/kbd-1.15.5-r1/temp/environment'. * Working directory: '/var/tmp/portage/sys-apps/kbd-1.15.5-r1/work' * S: '/var/tmp/portage/sys-apps/kbd-1.15.5-r1/work/kbd-1.15.5'
It fails with -O3, specifically with -ftree-vectorize. What is still strange is that tar emerges successfully with FEATURES="test"
reproduced. >>> Emerging (1 of 1) sys-apps/kbd-1.15.5-r1::gentoo * kbd-1.15.5.tar.gz SHA256 SHA512 WHIRLPOOL size ;-) ... [ ok ] >>> Unpacking source... >>> Unpacking kbd-1.15.5.tar.gz to /var/tmp/portage/sys-apps/kbd-1.15.5-r1/work tar: Skipping to next header tar: Exiting with failure status due to previous errors * ERROR: sys-apps/kbd-1.15.5-r1::gentoo failed (unpack phase): * failure unpacking kbd-1.15.5.tar.gz * * Call stack: * ebuild.sh, line 93: Called src_unpack * environment, line 1887: Called default * phase-functions.sh, line 770: Called default_src_unpack * phase-functions.sh, line 797: Called __eapi0_src_unpack * phase-helpers.sh, line 648: Called unpack 'kbd-1.15.5.tar.gz' * phase-helpers.sh, line 357: Called __unpack_tar 'gzip -d' * phase-helpers.sh, line 299: Called __assert_sigpipe_ok 'failure unpacking kbd-1.15.5.tar.gz' riros@riroshost ~/clion/bin $ emerge --info tar Portage 2.2.14 (python 2.7.9-final-0, default/linux/amd64/13.0/desktop/gnome/systemd, gcc-4.8.3, glibc-2.19-r1, 3.17.7-gentoo x86_64) ================================================================= System Settings ================================================================= System uname: Linux-3.17.7-gentoo-x86_64-Intel-R-_Core-TM-_i7-4702MQ_CPU_@_2.20GHz-with-gentoo-2.2 KiB Mem: 8099400 total, 2363436 free KiB Swap: 0 total, 0 free Timestamp of tree: Sun, 25 Jan 2015 19:30:01 +0000 ld GNU ld (Gentoo 2.24 p1.4) 2.24 app-shells/bash: 4.2_p53 dev-java/java-config: 2.2.0 dev-lang/perl: 5.18.2-r2 dev-lang/python: 2.7.9-r1, 3.4.1 dev-util/cmake: 2.8.12.2-r1 dev-util/pkgconfig: 0.28-r1 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.13.8 sys-apps/sandbox: 2.6-r1 sys-devel/autoconf: 2.13, 2.69 sys-devel/automake: 1.10.3-r1, 1.11.6-r1, 1.13.4 sys-devel/binutils: 2.24-r3 sys-devel/gcc: 4.8.3 sys-devel/gcc-config: 1.7.3 sys-devel/libtool: 2.4.4 sys-devel/make: 4.0-r1 sys-kernel/linux-headers: 3.16 (virtual/os-headers) sys-libs/glibc: 2.19-r1 Repositories: gentoo steam-overlay ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-pipe -fomit-frame-pointer -O3 -march=native -mtune=native" CHOST="x86_64-pc-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/php/apache2-php5.3/ext-active/ /etc/php/apache2-php5.4/ext-active/ /etc/php/apache2-php5.5/ext-active/ /etc/php/cgi-php5.3/ext-active/ /etc/php/cgi-php5.4/ext-active/ /etc/php/cgi-php5.5/ext-active/ /etc/php/cli-php5.3/ext-active/ /etc/php/cli-php5.4/ext-active/ /etc/php/cli-php5.5/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-pipe -fomit-frame-pointer -O3 -march=native -mtune=native" DISTDIR="/usr/portage/distfiles" 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" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="ru_RU.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j8" PKGDIR="/usr/portage/packages" 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" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/var/lib/layman/steam" USE="X a52 aac acl acpi ads aio alsa amd64 autoipd avahi bash-completion berkdb boost branding bzip2 c++0x cairo caps caps-ng cdda cdr clang cli client contrib cracklib creds crypt cups curl cxx cycles dbus dhclient djvu dri dts dvd dvdr eds egl emboss encode evo exif fam fftw firefox flac flash fpm freerdp gallium game-engine gbm gd gdb gdbm gflags gif git glamor gnome gnome-keyring gnome-online-accounts gnome3 gnutls gpm graphicsmagick gstreamer gtk gtk3 gudev highlight iconv icu introspection ipv6 jpeg jpeg2k json lcms ldap libnotify libsecret lzma mad matroska minizip mmx mng modemmanager modules mongodb mono mount mp3 mp4 mpeg multilib mysql mysqli nautilus ncurses networkmanager nls nptl nsplugin ogg openexr opengl openmp optimisememory pam pango pch pcre pdf pdo perl php player png policykit postgres ppds ppp pulseaudio python python3 qt3support qt4 readline s3tc samba sasl sdk sdl session shared-glapi smbclient sndfile soap socialweb sockets spell sqlite sse sse2 ssh ssl startup-notification steamfonts steamgames_source_engine stemmer subversion svg symlink systemd tcpd theora threads tiff truetype udev udisks unicode upower uvm vdpau vorbis vpx webgl webkit webm wxwidgets x264 xa xattr xcb xml xmlreader xmlwriter xslt xv xvid zip zlib" ABI_X86="64" 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="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CURL_SSL="openssl" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" GRUB_PLATFORMS="pc" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="ru" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-5" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_4" RUBY_TARGETS="ruby19 ruby20" USERLAND="GNU" VIDEO_CARDS="intel nvidia" 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" USE_PYTHON="2.7" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, SYNC ================================================================= Package Settings ================================================================= app-arch/tar-1.27.1-r2 was built with the following: USE="acl nls xattr -minimal (-selinux) -static" ABI_X86="64"
Apparently the above reports all show a Haswell-type CPU. I have the same issue with tar and kbd here on a Haswell-based Xeon (E3-1231v3). Furthermore I have the same CFLAGS (-O3 -march=native) set on an Ivy Bridge-based (i7-4820K) and a Sandy Bridge-based (i7-2500K) system where tar and kbd work without these problems. It looks like an issue with gcc 4.8.x on Haswells.. Portage 2.2.14 (python 3.3.5-final-0, default/linux/amd64/13.0, gcc-4.8.4, glibc-2.20-r2, 3.19.3 x86_64) ================================================================= System Settings ================================================================= System uname: Linux-3.19.3-x86_64-Intel-R-_Xeon-R-_CPU_E3-1231_v3_@_3.40GHz-with-gentoo-2.2 KiB Mem: 16465840 total, 3416660 free KiB Swap: 0 total, 0 free Timestamp of tree: Fri, 03 Apr 2015 02:45:01 +0000 ld GNU ld (Gentoo 2.24 p1.4) 2.24 distcc 3.1 x86_64-pc-linux-gnu [disabled] ccache version 3.1.9 [disabled] app-shells/bash: 4.2_p53 dev-lang/perl: 5.20.1-r4 dev-lang/python: 2.7.9-r1, 3.3.5-r1, 3.4.1 dev-util/ccache: 3.1.9-r4 dev-util/cmake: 2.8.12.2-r1 dev-util/pkgconfig: 0.28-r1 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.13.11 sys-apps/sandbox: 2.6-r1 sys-devel/autoconf: 2.69 sys-devel/automake: 1.13.4 sys-devel/binutils: 2.24-r3 sys-devel/gcc: 4.8.4 sys-devel/gcc-config: 1.7.3 sys-devel/libtool: 2.4.6 sys-devel/make: 4.1-r1 sys-kernel/linux-headers: 3.18 (virtual/os-headers) sys-libs/glibc: 2.20-r2 Repositories: gentoo x-portage ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA PUEL" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O3 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /var/bind" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.5/ext-active/ /etc/php/cgi-php5.5/ext-active/ /etc/php/cli-php5.5/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -pipe" DISTDIR="/usr/portage/distfiles" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distcc2 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" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="ftp://gentoo.digadd.de/gentoo http://mirror.switch.ch/mirror/gentoo/ http://gentoo.inode.at http://ftp.snt.utwente.nl/pub/os/linux/gentoo http://gentoo.oregonstate.edu http://www.ibiblio.org/pub/Linux/distributions/gentoo" LANG="en_US.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j8" PKGDIR="/usr/portage/packages" 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" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://gentoo.digadd.de/gentoo-portage" USE="acl acpi aes amd64 apache2 avx avx2 bzip2 caps cracklib crypt cups cxx fma3 gmp hardened hwdb ipv6 kerberos kmod ldap lm_sensors logrotate mmx mmxext mysql ncurses nfsv4 nls nptl nscd openrc pam parse-clocks pci pcre perl popcnt python readline samba sasl sensord session sharedmem slang sse sse2 sse3 sse4_1 sse4_2 ssl ssse3 symlink tcpd threads udev unicode usb userlocales xattr xml zlib" ABI_X86="64" APACHE2_MODULES="actions alias auth_basic auth_digest authn_anon authn_dbd authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock dbd deflate dir disk_cache env expires ext_filter file_cache filter headers ident imagemap include info log_config logio mem_cache mime mime_magic negotiation proxy proxy_ajp proxy_balancer proxy_connect proxy_http rewrite setenvif so speling status unique_id userdir usertrack vhost_alias" APACHE2_MPMS="worker" CPU_FLAGS_X86="aes avx avx2 fma3 mmx mmxext popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3" ELIBC="glibc" KERNEL="linux" OFED_DRIVERS="mlx4" OPENMPI_FABRICS="ofed" OPENMPI_OFED_FEATURES="rdmacm" PYTHON_SINGLE_TARGET="python3_3" PYTHON_TARGETS="python2_7 python3_3" USERLAND="GNU" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON ================================================================= Package Settings ================================================================= app-arch/tar-1.27.1-r2 was built with the following: USE="acl nls xattr -minimal (-selinux) -static" ABI_X86="64"
Reemerged world with -O2 and tar works correctly again.
(In reply to Vasco Steinmetz from comment #6) > Reemerged world with -O2 and tar works correctly again. why? just only emerge tar with -O2
Because in this case tar exhibits a directly (human) noticeable misbehavior. I cannot foresee how much more packages are probably also affected (=bad compiled), as most code in a system is seldomly run but could introduce erratically behavior at random times.
Is this still happening with newer GCCs? I'd really hope not, but if it is, please let us know.