net-firewall/ipsec-tools-0.6.7 (and I guess also earlier versions) looks for kernel-headers in /usr/src/linux/include (and some other places) but neither in /usr/include/linux nor in "${KERNEL_DIR}/include". Especially, if KERNEL_DIR is set, the latter should override /usr/src/linux/include, although I am not sure whether even /usr/include/linux should have further precedence. In any case, ignoring KERNEL_DIR and using /usr/src/linux instead is obsolete and not consistent with the behavior of other ebuilds using kernel headers. (I am aware that this is some sort of dupe of bug 76741, but it seems to me that the comments/patches of bug 76741 are rather out of date and do not refer to KERNEL_DIR anyway.)
Do you have a patch? I looked at the ebuild and it makes my eyes bleed...
I tested now again, and to my surprise KERNEL_DIR is now honoured. No idea what is different, because the ebuild was not changed. Probably some eclass has been fixed meanwhile. So I close this bug.
Excellent... *g*
