same with 0.52.7. Seems to work on my amd64 so I attach the emerge --info.
nc alpine # emerge --info
Portage 2.1.3.19 (uclibc/x86/hardened, gcc-3.4.6, uclibc-0.9.28.3-r2,
2.6.22-vsgrsec-r2 i686)
=================================================================
System uname: 2.6.22-vsgrsec-r2 i686 Intel(R) Core(TM)2 CPU 6400 @ 2.13GHz
Timestamp of tree: Wed, 16 Jan 2008 12:00:01 +0000
app-shells/bash: 3.2_p17-r1
dev-lang/python: 2.4.4-r6
dev-python/pycrypto: 2.0.1-r6
sys-apps/baselayout: 2.0.0_rc6-r1
sys-apps/sandbox: 1.2.18.1-r2
sys-devel/autoconf: 2.13, 2.61-r1
sys-devel/automake: 1.6.3, 1.8.5-r3, 1.9.6-r2, 1.10
sys-devel/binutils: 2.18-r1
sys-devel/gcc-config: 1.4.0-r4
sys-devel/libtool: 1.5.24
virtual/os-headers: 2.6.23-r3
ACCEPT_KEYWORDS="x86"
CBUILD="i386-gentoo-linux-uclibc"
CFLAGS="-march=i386 -Os -pipe -fomit-frame-pointer"
CHOST="i386-gentoo-linux-uclibc"
CONFIG_PROTECT="/etc /var/bind"
CONFIG_PROTECT_MASK="/etc/env.d /etc/fonts/fonts.conf /etc/gconf
/etc/gentoo-release /etc/php/apache2-php5/ext-active/
/etc/php/cgi-php5/ext-active/ /etc/php/cli-php5/ext-active/ /etc/revdep-rebuild
/etc/terminfo /etc/udev/rules.d"
CXXFLAGS="-Os -pipe"
DISTDIR="/var/cache/distfiles"
FEATURES="autoconfig buildpkg distlocks metadata-transfer nodoc noinfo noman
sandbox sfperms strict unmerge-orphans userfetch"
GENTOO_MIRRORS="http://distfiles.gentoo.org
http://distro.ibiblio.org/pub/linux/distributions/gentoo"
MAKEOPTS="-j3"
PKGDIR="/var/cache/packages/default"
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
--filter=H_**/files/digest-*"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/alpine-portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="X509 bitmap-fonts bri bzip2 cli cracklib dri encode expat extensions
hardened iproute2 ipv6 jpeg lua mad midi mmap mudflap ncurses netboot nonfsv4
ntfs ogg openmp oss pci pcmcia pic png pppd pri readline reflection rrdtool
sensord session snmp speex spl ssl tdb truetype truetype-fonts type1-fonts
uclibc uclibc++ udev usb userlocales wifi wordexp x86 xorg zaptel zlib"
ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file
hooks iec958 ioplug ladspa lfloat linear meter 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="uclibc" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux"
LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses
text" MISDN_CARDS="avmfritz hfcmulti hfcpci hfcsmini hfcsusb netjetpci sedlfax
w6692pci xhfc" USERLAND="GNU" VIDEO_CARDS="dummy fbdev v4l apm ark chips cirrus
cyrix epson glint i128 i740 i810 imstt mach64 mga neomagic nsc nv r128 radeon
rendition s3 s3virge savage siliconmotion sis sisusb tdfx tga trident tseng
vesa vga via voodoo"
Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL,
LDFLAGS, LINGUAS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS,
PORTAGE_RSYNC_EXTRA_OPTS
