I just tried to build cargo using rust-bin and that worked for me. We should possibly update the ebuild to reflect that: DEPEND="${COMMON_DEPEND} || ( >=dev-lang/rust-1.9.0:stable >=dev-lang/rust-bin-1.15.0 ) dev-util/cmake sys-apps/coreutils sys-apps/diffutils sys-apps/findutils sys-apps/sed" I pinned to 1.15.0 since that is the only version I'm testing.
Rust overlay use virtual/rust package.
It would be super helpfull to change the DEPEND to the virtual/rust package.
cargo-0.21.0 depends on virtual/rust.