Can you please have a look if virtual/awk is sufficient or if gawk is needed.
awk is used during build in db-Makefile, Makefile.in and src/Makefile.in, but in ways, which is compatible with the POSIX awk standard, so virtual/awk should be the right dependency. Or follow vapier's suggestion and get rid of the awk dependency completely as it is in the system set.
(In reply to comment #1) > Or follow vapier's suggestion and get rid of the awk dependency completely > as it is in the system set. Followed vapier's suggestion: + 24 Feb 2013; Christoph Junghans <ottxor@gentoo.org> + nss-db-2.2.3_pre1-r2.ebuild, nss-db-2.2.3_pre1-r3.ebuild: + dropped gawk from deps as it is in system set (bug #455686)