I installed binutils-2.23.0 ... with gmp, mpfr, mpc
... Then no system gcc is supposed to work.
Better uninstall / delete all the alien files from /usr/local/*.
! No alternative version of binutils, gmp, mpfr, mpc
can be installed to a system path !
If you for experimental reasons want to install non system versions,
please use './configure --prefix=/opt/test/' or another location,
which is so well hidden, that no system programs will find it.