GCC_NO_EXECUTABLES during CFE build on MinGW

Still trying to build the cfrontend on MinGW:

checking for additional debug build... no
checking for extra compiler flags for building...
checking for sys/types.h... (cached) yes
checking locale.h usability... yes
checking locale.h presence... yes
checking for locale.h... yes
checking float.h usability... yes
checking float.h presence... yes
checking for float.h... yes
checking for main in -lm... configure: error: Link tests are not allowed
make: *** [configure-target-libstdc++-v3] Error 1

Googling, I found these links:

So I've read some descriptions for why I might get this error:
1. Perhaps I'm missing a library or two?
2. Perhaps something is broken or configured wrong and it just can't find
(a library?) things?

Unfortunatly, this error message is very arcane and doesn't indicate what
is missing. The least it could do is report what file it was trying to
subject to a link test, but I can't seem to even get that information.

I've spent a few hours looking over the configure log but haven't got much
better information there.

Anybody know how to troubleshoot this one?