Can you please have a look if virtual/awk is sufficient or if gawk is needed.
Makefile actually makes a comment that nawk is supported and AWK=awk, so virtual/awk should be fine.
+ 24 Feb 2013; Sergey Popov <pinkbyte@gentoo.org> mgetty-1.1.36-r3.ebuild: + Change awk dependency to virtual/awk, wrt bug #455666 Checked with mawk and busybox awk implementations - all seems fine