Created attachment 407832 [details] shortened gmp stage2 build log As mentioned in the comments within bootstrap-prefix.sh, many binary distributions have separate packages for gcc and g++. The current script tries to accommodate this case, but leaves dev-libs/gmp with default flags which end up including cxx. This then fails during configure, as can be seen in the shortened stage2.log. Patch follows; I think it's easiest to add an entry into package.use in ${ROOT}/tmp so that it only affects stage2. Fixes the bug on systems that I tested with (Centos 7, Fedora 22).
Created attachment 407834 [details, diff] Add "dev-libs/gmp -cxx" to ${ROOT}/tmp/package.use in stage2
GCC 4.7.3 still compiles cleanly after this change, and stage3 starts by rebuilding all the compiler dependencies anyway so that this change disappears.
ok, pushed your fix
