C++ Problems (no g++, CXX=gcc yields '"/lib/cpp" fails sanity check')

[Weston C]

So, whistling along through a default build, the process hit a decided speedbump when make found g++ missing.

No problem, I thought, I'll just set CXX="gcc" in the environment and reconfigure and be on my way. But configure chokes with this and gives the following error:

checking how to run the C++ preprocessor... /lib/cpp
configure: error: C++ preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details.

As instructed, I did check 'config.log', but I'm afraid I don't see anything that means much to me -- the last bit of the file looks like part of a c header file containing macros, and then a line that says "configure: exit 1." I can see how cpp might be related, but not a specific error.

Any ideas here? What requirements might there be for cpp and what are the sanity tests?

Thanks!