All combinations of USE flags emerge and work fine on amd64.
It's worth noting that, with USE=nfs, I get
!!! All ebuilds that could satisfy "net-libs/libnfsidmap" have been masked.
!!! One of the following masked packages is required to complete your request:
- net-libs/libnfsidmap-0.17 (masked by: ~amd64 keyword)
I don't have NFS running anyway, so I didn't bother installing that.
Gentoo Base System version 1.12.5
Portage 2.1.1-r1 (default-linux/amd64/2006.1, gcc-4.1.1, glibc-2.4-r3,
2.6.15-gentoo-r72006040301 x86_64)
=================================================================
System uname: 2.6.15-gentoo-r72006040301 x86_64 AMD Athlon(tm) 64 Processor
3700+
Last Sync: Tue, 16 Jan 2007 03:20:01 +0000
app-admin/eselect-compiler: [Not Present]
dev-java/java-config: 1.3.7, 2.0.30
dev-lang/python: 2.4.3-r4
dev-python/pycrypto: 2.0.1-r5
dev-util/ccache: [Not Present]
dev-util/confcache: [Not Present]
sys-apps/sandbox: 1.2.17
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
sys-devel/binutils: 2.16.1-r3
sys-devel/gcc-config: 1.3.14
sys-devel/libtool: 1.5.22
virtual/os-headers: 2.6.11-r2
ACCEPT_KEYWORDS="amd64"
AUTOCLEAN="yes"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc"
CONFIG_PROTECT_MASK="/etc/env.d /etc/env.d/java/ /etc/gconf
/etc/java-config/vms/ /etc/revdep-rebuild /etc/terminfo"
CXXFLAGS="-O2 -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig collision-protect confcache digest distlocks
metadata-transfer multilib-strict sandbox sfperms strict test"
GENTOO_MIRRORS="http://gentoo.chem.wisc.edu/gentoo/"
PKGDIR="/usr/portage/packages"
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/local/portage"
SYNC="rsync://209.59.138.21/gentoo-portage"
USE="amd64 alsa_cards_ali5451 alsa_cards_als4000 alsa_cards_atiixp
alsa_cards_atiixp-modem alsa_cards_bt87x alsa_cards_ca0106 alsa_cards_cmipci
alsa_cards_emu10k1x alsa_cards_ens1370 alsa_cards_ens1371 alsa_cards_es1938
alsa_cards_es1968 alsa_cards_fm801 alsa_cards_hda-intel alsa_cards_intel8x0
alsa_cards_intel8x0m alsa_cards_maestro3 alsa_cards_trident
alsa_cards_usb-audio alsa_cards_via82xx alsa_cards_via82xx-modem
alsa_cards_ymfpci alsa_pcm_plugins_adpcm alsa_pcm_plugins_alaw
alsa_pcm_plugins_asym alsa_pcm_plugins_copy alsa_pcm_plugins_dmix
alsa_pcm_plugins_dshare alsa_pcm_plugins_dsnoop alsa_pcm_plugins_empty
alsa_pcm_plugins_extplug alsa_pcm_plugins_file alsa_pcm_plugins_hooks
alsa_pcm_plugins_iec958 alsa_pcm_plugins_ioplug alsa_pcm_plugins_ladspa
alsa_pcm_plugins_lfloat alsa_pcm_plugins_linear alsa_pcm_plugins_meter
alsa_pcm_plugins_mulaw alsa_pcm_plugins_multi alsa_pcm_plugins_null
alsa_pcm_plugins_plug alsa_pcm_plugins_rate alsa_pcm_plugins_route
alsa_pcm_plugins_share alsa_pcm_plugins_shm alsa_pcm_plugins_softvol berkdb
bitmap-fonts cli cracklib crypt cups dlloader dri elibc_glibc fortran gdbm gpm
iconv input_devices_evdev input_devices_keyboard input_devices_mouse ipv6
isdnlog kernel_linux libg++ ncurses nls nptl nptlonly pam pcre perl ppds pppd
python readline reflection session spl ssl tcpd truetype-fonts type1-fonts udev
unicode userland_GNU video_cards_apm video_cards_ark video_cards_ati
video_cards_chips video_cards_cirrus video_cards_cyrix video_cards_dummy
video_cards_fbdev video_cards_glint video_cards_i128 video_cards_i810
video_cards_mga video_cards_neomagic video_cards_nv video_cards_rendition
video_cards_s3 video_cards_s3virge video_cards_savage video_cards_siliconmotion
video_cards_sis video_cards_sisusb video_cards_tdfx video_cards_tga
video_cards_trident video_cards_tseng video_cards_v4l video_cards_vesa
video_cards_vga video_cards_via video_cards_vmware video_cards_voodoo xorg
zlib"
Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS,
LINGUAS, MAKEOPTS, PORTAGE_RSYNC_EXTRA_OPTS
