Installing Gentoo has been driving me nuts. Not only is the handbook flat out not funcitonal in some places (Like "make boot" not working after make and make module_install and genkernel failing unless you first do "emerge --ask sys-kernel/genkernel" which is further down in the docs)
It also takes ages. I might have to wait half an hour for a huge emerge job before I can even see what error it'll spit out.