Unfortunately, I do not have a simple testcase for reproducing this error so I am going to report the situation where pari-2.3.4-r1 fails: Pari is one of Sage's (not in portage, available via http://github.com/cschwan/sage-on-gentoo) dependencies which ships with a lot of tests. On amd64 a lot of tests fail (that means Sage exits with SIGSEGV) because of pari. On x86 this problem is not present. I found out that adding "-fno-strict-aliasing" solves the problem (note that this flag is present by default when compiling pari outside portage). Reproducible: Always Portage 2.1.8.3 (default/linux/amd64/10.0/desktop, gcc-4.3.4, glibc-2.10.1-r1, 2.6.31-gentoo-r6 x86_64) ================================================================= System uname: Linux-2.6.31-gentoo-r6-x86_64-AMD_Athlon-tm-_64_X2_Dual_Core_Processor_4200+-with-gentoo-1.12.13 Timestamp of tree: Mon, 19 Apr 2010 14:00:01 +0000 ccache version 2.4 [enabled] app-shells/bash: 4.0_p37 dev-lang/python: 2.6.4-r99 dev-python/pycrypto: 2.1.0_beta1 dev-util/ccache: 2.4-r7 dev-util/cmake: 2.6.4-r3 sys-apps/baselayout: 1.12.13 sys-apps/sandbox: 1.6-r2 sys-devel/autoconf: 2.63-r1 sys-devel/automake: 1.11.1 sys-devel/binutils: 2.18-r3 sys-devel/gcc: 4.3.4 sys-devel/gcc-config: 1.4.1 sys-devel/libtool: 2.2.6b virtual/os-headers: 2.6.30-r1 ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -march=k8 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/X11/xkb" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /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="-O2 -fno-strict-aliasing -march=k8 -pipe" DISTDIR="/usr/portage/distfiles" EMERGE_DEFAULT_OPTS="--with-bdeps y" FEATURES="assume-digests ccache distlocks fixpackages news nodoc parallel-fetch protect-owned sandbox sfperms strict unmerge-logs unmerge-orphans userfetch" GENTOO_MIRRORS="http://distfiles.gentoo.org" LDFLAGS="" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage/layman/sage-on-gentoo" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="X a52 aac acpi alsa amd64 berkdb bluetooth branding bzip2 cairo cdr cli consolekit cpudetection cracklib crypt cups cxx dbus dri dts dvd dvdr emboss encode exif fam firefox flac fortran gdbm gif git gpm hal iconv jpeg lcms libnotify mad mikmod mmx mng modules mp3 mp4 mpeg mudflap multilib ncurses nls nptl nptlonly ogg opengl openmp pam pango pcre pdf perl png ppds pppd python qt3support readline reflection session spell spl sse sse2 ssl startup-notification svg sysfs tcpd threads tiff truetype unicode usb vorbis x264 xcb xml xorg xulrunner xv xvid zlib" 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" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="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 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" ELIBC="glibc" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" RUBY_TARGETS="ruby18" USERLAND="GNU" VIDEO_CARDS="nvidia" Unset: CPPFLAGS, CTARGET, FFLAGS, INSTALL_MASK, LANG, LC_ALL, LINGUAS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS
Added "-fno-strict-aliasing"to the compile flags. Thanks!
