configure: error: C++ preprocessor "/lib/cpp" fails sanity check

[moseley@hank.org]

moseley@laptop:~$ echo "#include <stdio.h>" > foo.cc
moseley@laptop:~$ /lib/cpp foo.cc
cpp: installation problem, cannot exec `cc1plus': No such file or directory


I'm using on Sid:

ii  autoconf        2.57-11         automatic configure script builder
ii  cpp             3.3.1-2         The GNU C preprocessor.

cpp doesn't seem to depend on g++, where I believe cc1plus is installed.

Is this a broken package?  And if so, which one?

-- 
Bill Moseley
moseley@hank.org