Removal of RPC from glibc

So glibc upstream has removed the RPC interfaces, and this has made its
way into Fedora rawhide.  (It's actually been on its way out for many
years and was "obsoleted" in glibc 2.14 which was releases in 2011.)  In
any case, after this change, amanda fails to build unless I pass
--without-ndmp.

Configure as expected fails to find various RPC-related things:

checking for rpcgen... no
checking rpc/rpc.h usability... no
checking rpc/rpc.h presence... no
checking for rpc/rpc.h... no

So, my questions:

What do we lose by not shipping ndmp (amndmjob/ndmjob) in Fedora?  I
honestly don't even know what it is, but I don't want to just remove it
without understanding what it does.

Shouldn't --without-ndmp turn on automatically if there's no rpc headers
instead of failing the compilation?

ndmos_glib.h:51:2: error: #error rpc/rpc.h is required to compile ndmp-src

And finally, the solution is just to use libtirpc, but it puts its
headers in /usr/include/tirpc/rpc.  This could change in the future
since glibc is no longer conflicting, though.  Best would be to use
pkgconfig to get the proper locations for the libtirpc things, but
hacking autoconf to do that is a bit beyond me.

 - J<