the scipy ebuild needs blas-config to detect implementations. However, the ebuilds >=blas-atlas-3.7.0 use provide an eselect interface. If the scipy ebuild wants to use >=blas-atlas-3.7.0, it should use eselect (whose blas module doesn't work right now), or depend on blas-config.
Which scipy version? Could you try scipy-0.4.9 from the scientific overlay and report here? It fixes the blas-config dependency. I doubt scipy needs >=blas-atlas-3.7 since it is a development version.
We're reworking the eselect modules right now -- I'm just about to commit the new ones. So the next eselect release will have many changes that will help to deal with this.
Yeah, we should definitely fix blas-atlas to install a blas-config file before stabilizing on 3.7.
OK 3.7.11 now uses blas-config again. However something needs to get figured out soon because we're shortly going to unmask a new eselect interface. Preferably scipy should stop doing this checking altogether -- I know there was some reason for it, but it's not worth it.
scipy 0.5.1 no longer has this check.