media-libs/libgphoto2 installs a script in /lib/udev regardless of what the system ABI is. I agree that the script is not ABI dependent but sys-fs/udev installs all its scripts in /$(get_libdir)/udev anyway, so libgphoto2 has better follow suit. I suggest the econf line in the libgphoto2 ebuilds is changed to include udevscriptdir=/$(get_libdir)/udev \ instead of udevscriptdir=/lib/udev \
configuration problem. udev does install in /lib/udev it would seem. ignore me.