See http://forums.gentoo.org/viewtopic.php?p=6898600#6898600 for background. Basically, I didn't have this option set, and the build failed in a manner that didn't lead me directly to the source of the error. While I agree with phajdan.jr that over-zealous checking of kernel config at build time is bad, that's bad when the *runtime* kernel config is important. In this case, it's the build-time kernel, so I think it's reasonable to check for CONFIG_IA32_EMULATION Reproducible: Always Portage 2.1.10.11 (default/linux/amd64/10.0, gcc-4.4.5, glibc-2.13-r4, 2.6.39-gentoo-r3-2011111501 x86_64) ================================================================= System uname: Linux-2.6.39-gentoo-r3-2011111501-x86_64-Intel-R-_Core-TM-2_CPU_T5600_@_1.83GHz-with-gentoo-2.0.3 Timestamp of tree: Mon, 12 Dec 2011 02:45:02 +0000 app-shells/bash: 4.1_p9 dev-lang/python: 2.7.2-r3, 3.1.4-r3 dev-util/pkgconfig: 0.26 sys-apps/baselayout: 2.0.3 sys-apps/openrc: 0.9.4 sys-apps/sandbox: 2.5 sys-devel/autoconf: 2.68 sys-devel/automake: 1.11.1 sys-devel/binutils: 2.21.1-r1 sys-devel/gcc: 4.4.5, 4.5.3-r1 sys-devel/gcc-config: 1.4.1-r1 sys-devel/libtool: 2.4-r1 sys-devel/make: 3.82-r1 sys-kernel/linux-headers: 2.6.39 (virtual/os-headers) sys-libs/glibc: 2.13-r4 Repositories: gentoo ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=core2 -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /var/bind" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-march=core2 -O2 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="assume-digests binpkg-logs distlocks ebuild-locks fixlafiles fixpackages news parallel-fetch protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch" FFLAGS="" GENTOO_MIRRORS="http://www.cyberuse.com/gentoo/ http://mirror.mcs.anl.gov/pub/gentoo/" LDFLAGS="-Wl,--as-needed" MAKEOPTS="-j1" 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="" SYNC="rsync://rsync.us.gentoo.org/gentoo-portage" USE="acl amd64 berkdb bzip2 cli cracklib crypt cups cxx dri fortran gdbm gpm iconv ipv6 mmx modules mudflap multilib ncurses nls nptl nptlonly openmp pam pcre pppd readline session sse sse2 ssl sysfs tcpd threads unicode xml xml2 xorg 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 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 stage tables krita karbon braindump" 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 ubx" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" PHP_TARGETS="php5-3" RUBY_TARGETS="ruby18" USERLAND="GNU" VIDEO_CARDS="fbdev glint intel mach64 mga neomagic nouveau nv r128 radeon savage sis tdfx trident vesa via vmware dummy v4l" 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, LANG, LC_ALL, LINGUAS, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS
I misattributed and misunderstood Hu's concerns (copy/paste error, sorry), as he noted in the forums post. Hu makes the suggestion: If you absolutely must test before building, test whether a 32-bit do-nothing program can be built and run. That both catches IA32_EMULATION=n and catches broken 32-bit environments, which a simple kernel configuration check will miss. which makes a lot of sense. It also seems like runtime testing of kernel features via /proc/config.gz would be the way to go for such things, rather than looking for kernel source which may or may not be present or related to the running kernel. At any rate, a better and earlier error about this would be great, regardless of method.
Probably this is a similar issue to bug 154472 and bug 192286.
*** This bug has been marked as a duplicate of bug 326693 ***
