Multilib System without emul-linux Packages

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For 64bit systems it is sometimes necessary to execute 32bit binaries, e.g. if the application is only available as 32bit binary like Opera, Steam, Windows applications and games via wine, ... To achieve this, Gentoo has a multilib profile which offers some emul-linux packages that bundle some 32bit libraries. So if an application like Opera, Steam or wine gets installed, then it pulls the emul-linux packages it needs to run. This approach works but has at least two drawbacks:

  • The bundled libraries are several months old (based on the stable libraries in Gentoo). Owners of relatively modern graphic cards (1-2 years old) who want to play a game once in a while (without proprietary drivers) need the latest available drivers and libraries because versions older than a month may render even old games completely unplayable. If the performance is excellent with multimedia and desktop applications but very low with wine and steam (native or not), then the problem lies with the emul-linux packages.
  • Prepackaged software compiled by other people is not the Gentoo way where the user wants to set his USE-flags and compiler flags etc. by himself.

But the end of emul-linux is coming: Several months ago Gentoo packages introduced a new flag (abi_x86_32) which will also create 32bit libraries of every package where this flag has been activated. So the times where a user e.g. had a fast 64bit mesa-10.2 library for his RadeonSI card and a 32bit emul-linux-opengl bottleneck with mesa-10.0 are over: If everything is set up properly, emerge mesa will install the same version of mesa in 64bit and 32bit on the system; same USE-flags, same everything.

This document will show how to setup a Gentoo ~amd64 system for this new way of dealing with 32bit libraries. A stable amd64 system may not work this way but if the new feature is completely stable, it will be available to all users eventually.


The following steps are needed to setup the system for abi_x86_32:

  1. Unmerge all packages from Overlays that replace packages from the base system (like X11 packages from x11-overlay) and all packages that depend on emul-linux packages, because they will interfere with the transition process.
  2. Note which emul-linux packages are installed, remove and mask them
  3. Set the abi_x86_32 flag for those packages which were part of the previously uninstalled emul-linux packages. The flag may be set globally but it makes no sense to create additional 32bit binaries for really everything (a 32bit copy of your desktop and GUI applications is probably very useless)
  4. Recompile everything that changed (which may need several hours)

Detailed Guide

For this guide you need eix and gentoolkit installed unless you know how to achieve the same things without their functionality. The guide follows the steps from the overview above.

Dealing with Overlays

Removing overlay packages depends on what you have installed so it cannot be handled here. If dependency problems or USE-flag problems occur later, you will see which package caused it.

Remove emul-linux and all dependencies

To find out which packages depend on emul-linux packages, you can use the following shell command:

root #for EMUL in $(eix -I --only-names emul-linux); do equery depends $EMUL; done

Note which packages were printed, then unmerge them. Gcc might be seen among those packages because of its multilib flag and, of course, do NOT unmerge GCC.


root #eix -I --only-names emul-linux

to know which emul-packages you had installed, open and open the linked site listing the contents of the emul-packages.

Now unmerge all emul-packages and mask them by adding them to /etc/portage/package.mask

FILE /etc/portage/package.maskMasking all emul-linux packages
# mask emul-linux

Apply the abi_x86_32 flag

First, unmask abi_x86_32 flag by putting the following in /etc/portage/profile/use.mask. If the file does not exist, create it.

FILE /etc/portage/profile/use.maskUnmasking abi_x86_32 flag

Then, open /etc/portage/package.use, append all package names from the site to it and append to every package name the flag abi_x86_32, like so:

FILE /etc/portage/package.useSetting abi_x86_32
# app-emulation/emul-linux-x86-baselibs-20140508-r14  USE="development kerberos ldap pam" ABI_X86="-32" 39,395 kB
app-admin/gamin abi_x86_32
app-arch/bzip2 abi_x86_32
app-arch/xz-utils abi_x86_32
app-crypt/mit-krb5 abi_x86_32
app-text/libpaper abi_x86_32
dev-db/sqlite abi_x86_32
dev-lang/perl abi_x86_32
dev-lang/python abi_x86_32
dev-libs/dbus-glib abi_x86_32
dev-libs/elfutils abi_x86_32
dev-libs/expat abi_x86_32
dev-libs/glib abi_x86_32
dev-libs/gmp abi_x86_32
dev-libs/json-c abi_x86_32
dev-libs/libffi abi_x86_32
dev-libs/libgcrypt abi_x86_32
dev-libs/libgpg-error abi_x86_32
dev-libs/libnl abi_x86_32
dev-libs/libpcre abi_x86_32
dev-libs/libtasn1 abi_x86_32
dev-libs/libusb abi_x86_32
dev-libs/libusb-compat abi_x86_32
dev-libs/libxml2 abi_x86_32
dev-libs/libxslt abi_x86_32
dev-libs/lzo abi_x86_32
dev-libs/nettle abi_x86_32
dev-libs/nspr abi_x86_32
dev-libs/nss abi_x86_32
dev-libs/openssl abi_x86_32
dev-libs/udis86 abi_x86_32
media-libs/giflib abi_x86_32
media-libs/lcms abi_x86_32
media-libs/libart_lgpl abi_x86_32
media-libs/libjpeg-turbo abi_x86_32
media-libs/libmng abi_x86_32
media-libs/libpng abi_x86_32
media-libs/tiff abi_x86_32
media-sound/pulseaudio abi_x86_32
net-dialup/capi4k-utils abi_x86_32
net-dns/libidn abi_x86_32
net-libs/gnutls abi_x86_32
net-libs/libgssglue abi_x86_32
net-libs/libsoup abi_x86_32
net-libs/libtirpc abi_x86_32
net-libs/neon abi_x86_32
net-misc/curl abi_x86_32
net-nds/openldap abi_x86_32
net-print/cups abi_x86_32
net-wireless/bluez abi_x86_32
sys-apps/acl abi_x86_32
sys-apps/attr abi_x86_32
sys-apps/dbus abi_x86_32
sys-apps/file abi_x86_32
sys-apps/keyutils abi_x86_32
sys-apps/pciutils abi_x86_32
sys-apps/tcp-wrappers abi_x86_32
sys-apps/util-linux abi_x86_32
sys-auth/nss-mdns abi_x86_32
sys-auth/nss_ldap abi_x86_32
sys-auth/pam_ldap abi_x86_32
sys-devel/binutils abi_x86_32
sys-devel/gettext abi_x86_32
sys-devel/libperl abi_x86_32
sys-devel/libtool abi_x86_32
sys-devel/llvm abi_x86_32
sys-fs/e2fsprogs abi_x86_32
sys-fs/udev abi_x86_32
sys-libs/cracklib abi_x86_32
sys-libs/db abi_x86_32
sys-libs/e2fsprogs-libs abi_x86_32
sys-libs/gdbm abi_x86_32
sys-libs/gpm abi_x86_32
sys-libs/libavc1394 abi_x86_32
sys-libs/libraw1394 abi_x86_32
sys-libs/ncurses abi_x86_32
sys-libs/pam abi_x86_32
sys-libs/pwdb abi_x86_32
sys-libs/readline abi_x86_32
sys-libs/slang abi_x86_32
sys-libs/talloc abi_x86_32
sys-libs/zlib abi_x86_32

#app-emulation/emul-linux-x86-db-20140508-r1  USE="development" ABI_X86="-32" 1,470 kB
dev-db/myodbc abi_x86_32
dev-db/mysql abi_x86_32
dev-db/unixODBC abi_x86_32

# app-emulation/emul-linux-x86-medialibs-20140508-r6  USE="development" ABI_X86="-32" 11,058 kB
app-misc/lirc abi_x86_32
dev-libs/DirectFB abi_x86_32
dev-libs/fribidi abi_x86_32
dev-libs/libcdio abi_x86_32
dev-libs/liboil abi_x86_32
media-gfx/sane-backends abi_x86_32
media-libs/a52dec abi_x86_32
media-libs/faac abi_x86_32
media-libs/faad2 abi_x86_32
media-libs/gst-plugins-base abi_x86_32
media-libs/gstreamer abi_x86_32
media-libs/libcuefile abi_x86_32
media-libs/libdca abi_x86_32
media-libs/libdv abi_x86_32
media-libs/libdvdnav abi_x86_32
media-libs/libdvdread abi_x86_32
media-libs/libgphoto2 abi_x86_32
media-libs/libid3tag abi_x86_32
media-libs/libiec61883 abi_x86_32
media-libs/libmad abi_x86_32
media-libs/libmimic abi_x86_32
media-libs/libmms abi_x86_32
media-libs/libmpeg2 abi_x86_32
media-libs/libofa abi_x86_32
media-libs/libreplaygain abi_x86_32
media-libs/libshout abi_x86_32
media-libs/libsidplay abi_x86_32
media-libs/libtheora abi_x86_32
media-libs/libv4l abi_x86_32
media-libs/libvisual abi_x86_32
media-libs/libvpx abi_x86_32
media-libs/speex abi_x86_32
media-libs/taglib abi_x86_32
media-libs/x264 abi_x86_32
media-libs/xvid abi_x86_32
media-sound/lame abi_x86_32
media-video/ffmpeg abi_x86_32
media-video/mjpegtools abi_x86_32
sys-libs/libieee1284 abi_x86_32

# app-emulation/emul-linux-x86-opengl-20140508  USE="development" ABI_X86="-32" 48,065 kB
media-libs/freeglut abi_x86_32
media-libs/glew abi_x86_32
media-libs/glu abi_x86_32
media-libs/mesa abi_x86_32
x11-libs/libdrm abi_x86_32

# app-emulation/emul-linux-x86-soundlibs-20140508  USE="alsa development pulseaudio" ABI_X86="-32" 7,090 kB
dev-libs/libical abi_x86_32
media-libs/alsa-lib abi_x86_32
media-libs/alsa-oss abi_x86_32
media-libs/audiofile abi_x86_32
media-libs/flac abi_x86_32
media-libs/ladspa-sdk abi_x86_32
media-libs/libao abi_x86_32
media-libs/libmikmod abi_x86_32
media-libs/libmodplug abi_x86_32
media-libs/libogg abi_x86_32
media-libs/libsamplerate abi_x86_32
media-libs/libsndfile abi_x86_32
media-libs/libvorbis abi_x86_32
media-libs/portaudio abi_x86_32
media-libs/webrtc-audio-processing abi_x86_32
media-plugins/alsa-plugins abi_x86_32
media-plugins/alsaequal abi_x86_32
media-plugins/caps-plugins abi_x86_32
media-plugins/swh-plugins abi_x86_32
media-sound/cdparanoia abi_x86_32
media-sound/gsm abi_x86_32
media-sound/jack-audio-connection-kit abi_x86_32
media-sound/mpg123 abi_x86_32
media-sound/musepack-tools abi_x86_32
media-sound/pulseaudio abi_x86_32
media-sound/twolame abi_x86_32
media-sound/wavpack abi_x86_32
net-wireless/bluez abi_x86_32
sci-libs/fftw abi_x86_32

# app-emulation/emul-linux-x86-xlibs-20140508  USE="(development) opengl" ABI_X86="-32" 2,704 kB
media-libs/fontconfig abi_x86_32
media-libs/freetype abi_x86_32
x11-libs/libICE abi_x86_32
x11-libs/libSM abi_x86_32
x11-libs/libX11 abi_x86_32
x11-libs/libXScrnSaver abi_x86_32
x11-libs/libXau abi_x86_32
x11-libs/libXaw abi_x86_32
x11-libs/libXcomposite abi_x86_32
x11-libs/libXcursor abi_x86_32
x11-libs/libXdamage abi_x86_32
x11-libs/libXdmcp abi_x86_32
x11-libs/libXext abi_x86_32
x11-libs/libXfixes abi_x86_32
x11-libs/libXft abi_x86_32
x11-libs/libXi abi_x86_32
x11-libs/libXinerama abi_x86_32
x11-libs/libXmu abi_x86_32
x11-libs/libXp abi_x86_32
x11-libs/libXpm abi_x86_32
x11-libs/libXrandr abi_x86_32
x11-libs/libXrender abi_x86_32
x11-libs/libXt abi_x86_32
x11-libs/libXtst abi_x86_32
x11-libs/libXv abi_x86_32
x11-libs/libXvMC abi_x86_32
x11-libs/libXxf86dga abi_x86_32
x11-libs/libXxf86vm abi_x86_32
x11-libs/libpciaccess abi_x86_32
x11-libs/libvdpau abi_x86_32
x11-libs/libxcb abi_x86_32
x11-proto/scrnsaverproto abi_x86_32

It does not matter if you need or want all these packages, just set the flag in case it gets emerged. I also added

FILE /etc/portage/package.useSetting abi_x86_32 for wine
app-emulation/wine abi_x86_32

because my main motivation was to play games via wine and mostly every commercial Windows game comes as 32bit binary.

Update the System

Emerge everything that changed:

root #emerge --keep-going --update --newuse --deep --with-bdeps=y world

. It is imperative to emerge with dependency and newuse checks.

If emerge complains about missing useflags for some packages (it probably will!), add them to the /etc/portage/package.use file like you did for the emul-linux packages. In my case I needed to add

FILE /etc/portage/package.useSetting additional abi_x86_32 flags - EXAMPLE
dev-util/pkgconfig abi_x86_32
x11-proto/dri2proto abi_x86_32
x11-proto/xf86vidmodeproto abi_x86_32
x11-libs/pixman abi_x86_32
x11-proto/xineramaproto abi_x86_32
virtual/libudev abi_x86_32
media-libs/libsdl abi_x86_32
media-libs/libass abi_x86_32
x11-proto/xf86bigfontproto abi_x86_32
x11-proto/xf86dgaproto abi_x86_32
dev-libs/icu abi_x86_32
net-libs/libasyncns abi_x86_32
media-libs/harfbuzz abi_x86_32
x11-proto/xextproto abi_x86_32
net-libs/glib-networking abi_x86_32
app-i18n/enca abi_x86_32
media-libs/libwebp abi_x86_32
x11-proto/renderproto abi_x86_32
virtual/opengl abi_x86_32
virtual/libusb abi_x86_32
virtual/pkgconfig abi_x86_32
x11-proto/xproto abi_x86_32
x11-proto/recordproto abi_x86_32
virtual/libiconv abi_x86_32
x11-proto/compositeproto abi_x86_32
x11-libs/pango abi_x86_32
x11-proto/presentproto abi_x86_32
dev-lang/orc abi_x86_32
x11-proto/dri3proto abi_x86_32
virtual/jpeg abi_x86_32
media-libs/vo-aacenc abi_x86_32
sys-libs/libcap abi_x86_32
x11-proto/xcb-proto abi_x86_32
x11-proto/xf86driproto abi_x86_32
x11-proto/inputproto abi_x86_32
x11-proto/randrproto abi_x86_32
media-libs/opus abi_x86_32
media-gfx/graphite2 abi_x86_32
net-libs/libproxy abi_x86_32
x11-proto/videoproto abi_x86_32
virtual/libintl abi_x86_32
media-libs/libdvdcss abi_x86_32
x11-proto/glproto abi_x86_32
virtual/glu abi_x86_32
virtual/libffi abi_x86_32
x11-libs/cairo abi_x86_32
x11-libs/libxshmfence abi_x86_32
dev-libs/libpthread-stubs abi_x86_32
x11-proto/damageproto abi_x86_32
x11-proto/kbproto abi_x86_32
sys-devel/flex abi_x86_32
x11-proto/fixesproto abi_x86_32

but the exact list will most likely depend on your USE-flags and will vary!

After all has been rebuilt, it is a good idea to restart the system or at least X. Then emerge all applications that needed emul-linux packages before. If something still depends on these packages now, fill out a bug.

GNU Compiler Collection special case

The above will succeed until recompiling sys-devel/gcc is required and reached. This may happen depending on sys-devel/gcc[$USE] USE flags because the toolchain herd did not yet resolve bug #511832 for quite some time now. The associated patch may be an overkill but the fix seems almost too easy. So follow the next sub section for a workaround.

Dead END

After following the previous steps one will get in a dead end with various packages depending on emulation packages not yet converted to the newer multilib variant. So, to not waste such an effort after so much trouble to get emul cruft out of the system, a workaround is to create /etc/portage/profile, if not already created, and add the emulation packages pulled in by those remaining dependencies, like GNU Compiler Collection case, in package.provided. At this point, one should be fine to go for the time being. Until those problematic packages get converted to the new multilib standard, this workaround will remain a safe net avoiding the numerous issues related to having emulation packages when using ~arch or simply for performance related issues.