Due to a thinko in debian/rules2, the compiler detected during the configury becomes gcc (2.95), not gnatgcc (3.2). Introduced with debian/rules2 1.7. So all version up to and including 1:3.2.1-1 are probably affected. You'll see an empty libgnat.a in the package.
For a manual build, you need a gnat-3.2 (<< 1:3.2.1-1). Corrected packages are already built for hppa and i386, sparc and powerpc are currently building. arm and m68k are not affected, so build failures are likely on alpha, ia64, mips, mipsel and s390. Maybe you want to build these packages by hand (see http://ftp-master.debian.org/~doko/gcc-3.2 for the source package). Please send a note to the list, if you build for one of these architectures. Matthias PS: Let's see what I broke on this Friday, 13th ...