The ebuild for mergelog 4.5 is missing the amd64 keyword. I've sucessfully tested the tool on a dual Opteron system. The software has not changed since April 2001, and probably should be marked as x86 instead of ~x86. http://mergelog.sourceforge.net/
Also functional for me on amd64. For such a simple utility, it's hard to say whether the lack of upgrades since 2001 is because it's "done", or because it's not maintained anymore.
Gentoo Base System version 1.12.4 Portage 2.1.1 (default-linux/amd64/2006.0, gcc-3.4.6, 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: Sat, 07 Oct 2006 14:50:01 +0000 ccache version 2.3 [disabled] app-admin/eselect-compiler: [Not Present] dev-java/java-config: [Not Present] dev-lang/python: 2.4.3-r1 dev-python/pycrypto: 2.0.1-r5 dev-util/ccache: 2.3 dev-util/confcache: [Not Present] sys-apps/sandbox: 1.2.17 sys-devel/autoconf: 2.13, 2.59-r7 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-r2 sys-devel/gcc-config: 1.3.13-r3 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 -march=k8 -msse3 -Os -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc" CONFIG_PROTECT_MASK="/etc/env.d /etc/gconf /etc/revdep-rebuild /etc/terminfo" CXXFLAGS="-O2 -pipe -march=k8 -msse3 -Os -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig confcache digest distlocks metadata-transfer sandbox sfperms strict" GENTOO_MIRRORS="http://gentoo.chem.wisc.edu/gentoo/" LINGUAS="" MAKEOPTS="-j2" 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://rsync.us.gentoo.org/gentoo-portage" USE="amd64 alsa apache2 berkdb bitmap-fonts cli crypt cups dlloader dri eds elibc_glibc encode foomaticdb fortran gif gpm imlib input_devices_evdev input_devices_keyboard input_devices_mouse ipv6 isdnlog jpeg kernel_linux lzw lzw-tiff ncurses nls nptl nptlonly opengl pam pcre perl png pppd python qt3 qt4 readline reflection session spell spl ssl tcpd threads tiff truetype-fonts type1-fonts usb userland_GNU vhosts 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 xml xml2 xorg xv zlib" Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, PORTAGE_RSYNC_EXTRA_OPTS
Added ~amd64 KEYWORD.
