rustup run 1.9.0 is not an alias for rustup run stable when stable version is 1.9.0

[nagisa]

It probably should be equivalent.

[shepmaster]

I'm pretty sure it will fit in the same code paths, but I'd like to extend this to rustup default and stable-${date}.

[tesuji]

Is this really an issue now? @kinnison

[kinnison]

this "issue" remains because the toolchain name won't match. Not sure if there's an efficient way to determine which toolchain to run in that context other than enumerating them all and checking that there's exactly one which matches the given version