What libunistring does guile need?

[Keith Wright]

I am trying to install guile from source tarball.
Of course, I had to install a couple of other things (gmp,m4,etc.)
but that's done.  gmp from source, other things with apt-get.
I'm stuck on libunistring.  It seems libunistring is not in Debian
but I have libunistring2 already installed:

   kwright@fcs26:~/.build/guile-3.0.9$ ./configure
   configure: error: GNU libunistring is required, please insstall it.

   root@fcs26:~# apt-get install libunistring
   E: Unable to locate package libunistring

   root@fcs26:~# apt-get install libunistring2
   libunistring2 is already the newest version (1.0-2).

What should I do?

   -- Keith