glib-2.38.2-r1.ebuild has this: pkg_setup() { if use kernel_linux ; then CONFIG_CHECK="~INOTIFY_USER" if use test; then CONFIG_CHECK="~IPV6" WARNING_IPV6="Your kernel needs IPV6 support for running some tests, skipping them." export IPV6_DISABLED="yes" fi linux-info_pkg_setup fi } src_prepare() { ... # Some tests need ipv6, upstream bug #667468 if [[ -n "${IPV6_DISABLED}" ]]; then sed -i -e "/socket\/ipv6_sync/d" gio/tests/socket.c || die sed -i -e "/socket\/ipv6_async/d" gio/tests/socket.c || die sed -i -e "/socket\/ipv6_v4mapped/d" gio/tests/socket.c || die fi ... } It means ipv6 tests are disabled for any system with linux kernel. If ipv6 module is compiled and loaded, then these tests should work fine, so why disable them in such case? I googled how to check if ipv6 is actually enabled in linux system, found these howtos: http://www.tldp.org/HOWTO/Linux+IPv6-HOWTO/systemcheck-kernel.html#AEN719 http://www.cyberciti.biz/faq/check-for-ipv6-support-in-linux-kernel/ Both suggest using '[ -f /proc/net/if_inet6 ]', seems like best solution for ebuild. P.S. bug number #667468 sure is wrong.
Applied this to the ebuild as it effectively blocked all testing of IPv6 even on ipv6 enabled machines. Thanks for reporting. https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=7cc8b1b22ee34d6b0c84ba5e822fb1a0def6fc01