portage-2.1.2_rc1-r7 seems not to be aware of the contents of that variable. It just displays the whole backends stuff like regular USE flags: *** # emerge -puDvtN world These are the packages that would be merged, in reverse order: Calculating world dependencies... done! [nomerge ] app-emulation/wine-0.9.25 USE="X alsa cups dbus gif glut hal jpeg lcms opengl scanner -arts -debug -esd -jack -ldap -nas -ncurses -oss -xml" [ebuild R ] media-gfx/sane-backends-1.0.18-r2 USE="usb -ipv6 -sane_backends_abaton% -sane_backends_agfafocus% -sane_backends_apple% -sane_backends_artec% -sane_backends_artec_eplus48u% -sane_backends_as6e% -sane_backends_avision% -sane_backends_bh% -sane_backends_brother% -sane_backends_canon% -sane_backends_canon630u% -sane_backends_canon_pp% -sane_backends_coolscan% -sane_backends_coolscan2% -sane_backends_dc210% -sane_backends_dc240% -sane_backends_dc25% -sane_backends_dmc% -sane_backends_epson% -sane_backends_fujitsu% -sane_backends_genesys% -sane_backends_gphoto2% -sane_backends_gt68xx% -sane_backends_hp% -sane_backends_hp3500% -sane_backends_hp4200% -sane_backends_hp5400% -sane_backends_hpsj5s% -sane_backends_ibm% -sane_backends_leo% -sane_backends_lexmark% -sane_backends_ma1509% -sane_backends_matsushita% -sane_backends_microtek% -sane_backends_microtek2% -sane_backends_mustek% -sane_backends_mustek_pp% -sane_backends_mustek_usb% -sane_backends_mustek_usb2% -sane_backends_nec% -sane_backends_net% -sane_backends_niash% -sane_backends_pie% -sane_backends_pint% -sane_backends_plustek% -sane_backends_plustek_pp% -sane_backends_pnm% -sane_backends_qcam% -sane_backends_ricoh% -sane_backends_s9036% -sane_backends_sceptre% -sane_backends_sharp% -sane_backends_sm3600% -sane_backends_sm3840% -sane_backends_snapscan% -sane_backends_sp15c% -sane_backends_st400% -sane_backends_stv680% -sane_backends_tamarack% -sane_backends_teco1% -sane_backends_teco2% -sane_backends_teco3% -sane_backends_test% -sane_backends_u12% -sane_backends_umax% -sane_backends_umax1220u% -sane_backends_umax_pp% -sane_backends_v4l% (-gphoto2%) (-v4l%)" 0 kB [5] **** This happenend *just after* merging that version of portage after a sync. No package had a pending update in the moment I did "emerge --sync". Info: Portage 2.1.2_rc1-r7 (default-linux/amd64/2006.1/desktop, gcc-4.1.1, glibc-2.5-r0, 2.6.18.1 x86_64) ================================================================= System uname: 2.6.18.1 x86_64 AMD Sempron(tm) Processor 3000+ Gentoo Base System version 1.12.6 Last Sync: Wed, 15 Nov 2006 23:00:04 +0000 dev-lang/python: 2.4.4 dev-python/pycrypto: 2.0.1-r5 sys-apps/sandbox: 1.2.18.1 sys-devel/autoconf: 2.13, 2.60 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10 sys-devel/binutils: 2.17 sys-devel/gcc-config: 1.3.14 sys-devel/libtool: 1.5.22 virtual/os-headers: 2.6.17-r1 ACCEPT_KEYWORDS="amd64 ~amd64 ~x86" AUTOCLEAN="yes" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -march=athlon64 -pipe -msse3" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/share/X11/xkb /usr/share/config" CONFIG_PROTECT_MASK="/etc/env.d /etc/gconf /etc/revdep-rebuild /etc/terminfo" CXXFLAGS="-O2 -march=athlon64 -pipe -msse3" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks fixpackages metadata-transfer sandbox sfperms strict" GENTOO_MIRRORS="http://pandemonium.tiscali.de/pub/gentoo/ ftp://ftp.caliu.info/pub/gentoo/ " LANG="es_ES.UTF-8" LC_ALL="es_ES.UTF-8" LDFLAGS="-Wl,-O1 -Wl,-z,now" LINGUAS="es en" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_RSYNC_EXTRA_OPTS="--bwlimit=50" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/portage/local /usr/portage/local/layman/sunrise /usr/portage/local/layman/berkano /usr/portage/local/layman/pro-audio /usr/portage/local/layman/flameeyes-overlay" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="amd64 3ds X alsa apache2 asf berkdb bzip2 cairo cdparanoia cdr cgi cle266 cli cracklib crypt cups curl dbus dlloader dmi dri dts dv dvb dvd dvdr dvdread eds elibc_glibc emboss encode fam ffmpeg firefox flash foomaticdb fortran freetype ggi gif gimp glitz glut gnome gpm gtk gtk2 hal hfs iconv idn input_devices_evdev input_devices_keyboard input_devices_mouse input_devices_ps2mouse isdnlog jfs jpeg kde kernel_linux kipi lcms libg++ linguas_en linguas_es mad mikmod mng modplug mozsvg mozxmlterm mp3 mpeg music mysql ncurses nls nomac nptl nptlonly ogg openal opengl pam pcre perl png pppd profile python qt3 qt4 quicktime readline reflection reiser4 sasl scanner sdl session slp sndfile soundtouch speex spell spl ssl svg taglib tcpd threads tiff truetype truetype-fonts type1-fonts udev unicode usb userland_GNU video_cards_nv video_cards_nvidia video_cards_vesa vorbis wmf xanim xml2 xorg xpm xprint xrandr xv xvmc zlib" Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK Forum: http://forums.gentoo.org/viewtopic-t-516691-highlight-.html?sid=1f0aa395ddddc85ddc7d3eea55908a7b
SANE_BACKENDS is not a valid USE_EXPAND (see make.defaults in profiles), and the official ebuild in portage does not have SANE_BACKENDS in IUSE either, your ebuild comes from some overlay - see that [5] in the emerge output. INVALID.
