>
> > Maybe a resync for dev-lang/rust-1.23.0-r1::gentoo helps. But
> > before you emerge, be aware of bug #646092 [1] (where I also ran
> > into). For me [2] solves the described issue.
> >
> >
> > References:
> >  - [1] <https://bugs.gentoo.org/show_bug.cgi?id=646092>
> >  - [2] <https://github.com/gentoo/gentoo/pull/7000>
>
> Well, it worked, with the 23.0-r1  release -- thanks much!
>

Since you've built rust you might be attempting to build firefox 58. If so,
it doesnt like distcc...