Can you please have a look if virtual/awk is sufficient or if gawk is needed.
awk is only used in create-help.sh, but only in very simple and posix-conform ways, so virtual/awk is fine.
+ 02 Mar 2013; Christoph Junghans <ottxor@gentoo.org> topgit-0.8.ebuild: + switched to virtual/awk (bug #455728)