gentoo gnunet build fails with MHD_post_process linker error

gnunet ebuild (zugaina layman overlay) fails with linker errors about MHD_destroy_post_processor and MHD_post_process ?

Add to /etc/portage/package.use:

net-libs/libmicrohttpd  messages

emerge libmicrohttpd again, and then emerge gnunet.

Success!

(at least for me)