--with-gcc does not work well

[Kazu Yamamoto ( 山本和彦 )]

>> For GCC, "cc" is guessed.
> 
> This is probably because the C compiler is guessed from the value of
> the CC environment variable, see the --help flag of "configure":

I'm sure that I don't set the CC environment variable. And specifying
CC=gcc47 does not solve this.

--Kazu