При сборке выдаёт ошибку:
checking for nss-config... /usr/bin/nss-config
checking for NSS - version >= 3.12.10... yes
checking for YASM assembler... checking for yasm... yasm
checking for jpeg_destroy_compress in -ljpeg... yes
checking for gzread in -lz... yes
checking for png_get_valid in -lpng... yes
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
*** Fix above errors and then restart with "make -f client.mk build"
make[2]: *** [configure] Error 1
make[2]: Leaving directory `/var/tmp/portage/www-client/firefox-6.0/work/mozilla-release'
make[1]: *** [obj-x86_64-unknown-linux-gnu/Makefile] Error 2
make[1]: Leaving directory `/var/tmp/portage/www-client/firefox-6.0/work/mozilla-release'
make: *** [build] Error 2
emake failed
* ERROR: www-client/firefox-6.0 failed (compile phase):
* emake failed
*
* Call stack:
* ebuild.sh, line 56: Called src_compile
* environment, line 6688: Called die
* The specific snippet of code:
* CC="$(tc-getCC)" CXX="$(tc-getCXX)" LD="$(tc-getLD)" MOZ_MAKE_FLAGS="${MAKEOPTS}" emake -f client.mk || die "emake failed";
*
* If you need support, post the output of 'emerge --info =www-client/firefox-6.0',
* the complete build log and the output of 'emerge -pqv =www-client/firefox-6.0'.
* The complete build log is located at '/var/tmp/portage/www-client/firefox-6.0/temp/build.log'.
* The ebuild environment file is located at '/var/tmp/portage/www-client/firefox-6.0/temp/environment'.
* S: '/var/tmp/portage/www-client/firefox-6.0/work/mozilla-release'
Подскажите, пожалуйста, чего ему не хватает?
То есть, чего - понятно. Не хватает поддержки APNG в системной libpng (если я правильно перевёл, конечно).
Вопрос - КАК это исправить?

.