artifact-app fails to "cargo install" with nightly

[talios]

Hi all,

I initially raised this at vitiral/artifact#227 and was redirected to raise as a potential rust-nightly issue.

This is on OSX High Sierra - Installing artifact via cargo +stable install artifact-app works, whereas cargo +nightly install artifact-app fails to build with:

error[E0283]: type annotations required: cannot resolve `std::path::Component<'_>: std::convert::AsRef<_>`
  --> src/utils.rs:40:38
   |
40 |                     remaining.push(a.as_ref());
   |                                      ^^^^^^

error: aborting due to previous error

as the compilation error.

[sfackler]

Caused by #46985.

[vitiral]

Thanks @talios

[Mark-Simulacrum]

Closing in favor of #48716.