I decided to fiddle with Mozilla Firefox by compiling it manually to see if I could get PGO enabled based on system information at Mozilla's bugzilla (https://bugzilla.mozilla.org/show_bug.cgi?id=418866). I used a .mozconfig file that had "--with-system-png" enabled and firefox's ./configure script failed citing: checking for png_get_acTL in -lpng... no configure: error: --with-system-png won't work because the system's libpng doesn't have APNG support There is no use flag to enable APNG support in libpng, so this is a problem because it means that www-client/mozilla-firefox is building with its own libpng library when I believe that Gentoo's policy is to rely on the system libraries as much as possible. Reproducible: Always Steps to Reproduce: 1. Get the firefox source code and extract it. 2. Make a .mozconfig file with the following contents: . $topsrcdir/browser/config/mozconfig ac_add_options --with-system-png 3. Run the configure script I am running a ~amd64 system with www-client/mozilla-firefox-3.6.3: # emerge --info Portage 2.1.8.3 (default/linux/amd64/10.0/no-multilib, gcc-4.4.3, glibc-2.11-r1, 2.6.33.2 x86_64) ================================================================= System uname: Linux-2.6.33.2-x86_64-Intel-R-_Core-TM-2_Quad_CPU_Q9550_@_2.83GHz-with-gentoo-2.0.1 Timestamp of tree: Sat, 17 Apr 2010 19:45:01 +0000 ccache version 2.4 [enabled] app-shells/bash: 4.1_p5 dev-java/java-config: 2.1.10 dev-lang/python: 2.6.5-r1, 3.1.2-r2 dev-util/ccache: 2.4-r8 dev-util/cmake: 2.8.1-r1 sys-apps/baselayout: 2.0.1 sys-apps/openrc: 0.6.1-r1 sys-apps/sandbox: 2.2 sys-devel/autoconf: 2.13, 2.65 sys-devel/automake: 1.8.5-r4, 1.9.6-r3, 1.10.3, 1.11.1 sys-devel/binutils: 2.20.1 sys-devel/gcc: 4.4.3 sys-devel/gcc-config: 1.4.1 sys-devel/libtool: 2.2.6b virtual/os-headers: 2.6.33 ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O3 -pipe -march=core2 -msse4.1 -mcx16 -msahf --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144 -floop-interchange -floop-strip-mine -floop-block -ftree-loop-linear -fgcse-sm -fgcse-las -ftree-loop-im -ftree-loop-ivcanon -fivopts -frename-registers -fweb" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/X11/xkb /usr/share/config /var/lib/hsqldb" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CPPFLAGS="-O3 -pipe -march=core2 -msse4.1 -mcx16 -msahf --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144 -floop-interchange -floop-strip-mine -floop-block -ftree-loop-linear -fgcse-sm -fgcse-las -ftree-loop-im -ftree-loop-ivcanon -fivopts -frename-registers -fweb" CXXFLAGS="-O3 -pipe -march=core2 -msse4.1 -mcx16 -msahf --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144 -floop-interchange -floop-strip-mine -floop-block -ftree-loop-linear -fgcse-sm -fgcse-las -ftree-loop-im -ftree-loop-ivcanon -fivopts -frename-registers -fweb" DISTDIR="/usr/portage/distfiles" FEATURES="assume-digests buildpkg ccache distlocks fixpackages news parallel-fetch protect-owned sandbox sfperms strict unmerge-logs unmerge-orphans userfetch" FFLAGS="-O3 -pipe -march=core2 -msse4.1 -mcx16 -msahf --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144 -floop-interchange -floop-strip-mine -floop-block -ftree-loop-linear -fgcse-sm -fgcse-las -ftree-loop-im -ftree-loop-ivcanon -fivopts -frename-registers -fweb" GENTOO_MIRRORS="http://distfiles.gentoo.org" LDFLAGS="-Wl,-O1" LINGUAS="en" MAKEOPTS="-j5" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY=" " SYNC="rsync://rsync.namerica.gentoo.org/gentoo-portage" USE="X acl alsa amd64 berkdb bzip2 cdr cli consolekit cracklib crypt cups cxx dbus dri dvd dvdr fftw fortran gd gdbm gif gnutls gpm iconv ipv6 java java6 jpeg kde midi mmx mng modules mudflap ncurses nls nptl nptlonly nsplugin ntpl opengl openmp pam pcre perl png pppd python qt3 qt3support qt4 readline reflection session spl sse sse2 sse3 ssl ssse3 svg sysfs tcpd tiff udev unicode xml xorg zlib" ALSA_CARDS="ens1371" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul 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="glibc" INPUT_DEVICES="keyboard vmmouse" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="en" RUBY_TARGETS="ruby18" USERLAND="GNU" VIDEO_CARDS="vmware" Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS
*** This bug has been marked as a duplicate of bug 183370 ***
