Can you please have a look if virtual/awk is sufficient or if gawk is needed.
+ 09 Feb 2013; Daniel Pielmeier <billie@gentoo.org> + mjpegtools-2.0.1_rc1.ebuild: + Use virtual/awk. This fixes bug #455740. Fixed. I have tested it on my system with all implementations and it seems to work fine. BTW: /usr/lib/portage/bin/misc-functions.sh from portage calls gawk directly.