The Gentoo FAQ suggests you may wish to edit the /usr/portage/scripts/bootstrap.sh script after reviewing it - and indeed, we will do so, because there are two ‘gotchas’ lurking in the above proposed emerge list. The first problem is that the C standard library that the bootstrap intends to rebuild is a virtual (virtual/libc); however, in Portage, emerging a virtual package does not, by default, cause any already-installed package that satisfies that virtual (in our case, sys-libs/glibc) to be rebuilt - which we want.