Error installing `1.50-x86_64-unknown-linux-musl` toolchain on macOS

[probablykasper]

Installing the <version>-x86_64-unknown-linux-musl toolchain worked for Rust 1.49, but doesn't in Rust 1.50. I'm on x86_64 macOS 10.14.6.

Logs from running rustup toolchain install 1.50-x86_64-unknown-linux-musl:

warning: toolchain '1.50-x86_64-unknown-linux-musl' may not be able to run on this system.
warning: If you meant to build software to target that platform, perhaps try `rustup target add x86_64-unknown-linux-musl` instead?
info: syncing channel updates for '1.50-x86_64-unknown-linux-musl'
info: latest update on 2021-02-11, rust version 1.50.0 (cb75ad5db 2021-02-10)
info: downloading component 'cargo'
info: downloading component 'clippy'
info: downloading component 'rust-docs'
info: downloading component 'rust-std'
info: downloading component 'rustc'
info: downloading component 'rustfmt'
info: installing component 'cargo'
info: using up to 500.0 MiB of RAM to unpack components
info: installing component 'clippy'
info: installing component 'rust-docs'
 14.7 MiB /  14.7 MiB (100 %)   9.2 MiB/s in  1s ETA:  0s
info: rolling back changes
error: failed to install component: 'rust-docs-x86_64-unknown-linux-musl', detected conflict: '"share/doc/rust/html/std/keyword.self.html"'

Not 100% sure if this is the right repo for it, please let me know if not.

[probablykasper]

This probably should go in https://github.com/rust-lang/rustup

Edit: I was wrong

[ehuss]

Although it is a bit unfortunate that rustup fails to install, I think the underlying problem of rustdoc creating files that only differ in case is tracked in #25879 and this particular case is #80504.

[probablykasper]

@ehuss Any idea why this specific issue started in 1.50, and why it's not there in 1.50-x86_64-apple-darwin or 1.50-x86_64-pc-windows-gnu?

[ehuss]

It doesn't apply to the x86_64-apple-darwin targets because those are built on macOS with a case-insensitive filesystem, so the files get stomped on during build time and only one appears in the distribution.

I don't think there is any difference between gnu and musl, they both fail for me.

As for why it changed in 1.50, the way the distribution manifest is created changed as part of #79788 (I think, it changed around the day that merged), so that instead of just indicating there is a single directory to install, the manifest now lists every file individually.

cc @kinnison
cc @pietroalbini Pietro: I'm not sure if it was intended that the component manifest for rust-docs changed from listing a single directory (dir:share/doc/rust/html) to listing each file individually. I'm not sure it matters much either way, but I'm not too familiar with how the manifest is used.

[probablykasper]

@ehuss Ah got it, I'm guessing Windows is built with a case-insensitive filesystem as well then. Is there a good reason Linux isn't?

[kinnison]

@probablykasper Linux by default does not use case-insensitive filesystems.

[jyn514]

I marked this as T-infra since I assume you want this to specifically track the failure to install the docs. If you just want to track the name collision this should be closed as a duplicate.