virtual/blas-1.0 was removed, the same applies to virtual/lapack. Both packages don't provide any stable candidates, so it's unclear how Octave can be installed in such conditions. What happened?
Now, with this above update virtual/{blas,cblas,lapack}-3.8 were deleted. And gone the possible usage of sci-libs/lapack-3.8.0 why???
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=ab892667224c65ec694d6adbda30c3a1eed67a92