When you try to emerge jpeg-6b-r3 you get this error.
make:./libtool : command not found
make: *** [jpcapimin.Lo] error 127
Error: the ebuild did not complete succesfully
Function src_compil , line -147, errorcode 2
No error message
It also mentions something about the host type not being able to be "none"
if you change $host in jpeg-6b-r3.ebuild to $chost (as it is defined in
/etc/make.conf) it merges correctly.