Confusing install error message when nightly/beta releases are missing

[jfirebaugh]

I wanted to install the beta channel in order to test Rust 2018, but I ran into rust-lang/rust#55817. It was difficult to figure out what was happening; I was quite confused by the rustup output:

$ rustup install beta
info: syncing channel updates for 'beta-x86_64-apple-darwin'
info: latest update on 2018-11-09, rust version 1.31.0-beta.5 (bf00632e3 2018-11-08)

  beta-x86_64-apple-darwin unchanged - (toolchain not installed)

I thought I must be using the wrong rustup commands, and spent a lot of time trying different things before concluding that it was not user error.

Could rustup have better error diagnostics for this case? It's come up a few times now: rust-lang/rust#55817, rust-lang/rust#46391, rust-lang/rust#46396.

[kinnison]

I believe that this won't happen on beta any more thanks to process changes; but I wonder if there's a way we can reproduce this now. Does anyone know if we have the beta manifests from the past?

[kinnison]

There has been no movement on this, nor any reproduction of it. I'm going to close the issue. If something like this comes up in the future, we can open a fresh issue to discuss.