"Target not found", even though it exists

[golddranks]

If I try to set nightly-x86_64-unknown-linux-musl as the default toolchain, I get an error:

$ rustup default nightly-x86_64-unknown-linux-musl
info: syncing channel updates for 'nightly-x86_64-unknown-linux-musl'
error: target not found: 'x86_64-unknown-linux-musl'

But obviously the target exists because I can compile with cargo build --target=x86_64-unknown-linux-musl just fine.

[golddranks]

Okay, maybe it's just that the error message is unclear? I think rustup default sets the host toolchain, and musl is available only as a cross-compile target? Is that right?

[xen0n]

Yeah the default and toolchain subcommands all deal with host toolchains -- the executables and libraries that make up the compiler. You manage targets through the target subcommand.

[golddranks]

Okay, then the message should say "host triplet not found", no?

[brson]

Yes I think 'host' would be clearer in this case.

[brson]

This could possibly even determine that the triple is a valid target and make a suggestion to run target add.

[xen0n]

Hmm, #826 seems relevant too. Might as well fix both at once. We should check on update (update, install, toolchain add and the like are all crazy aliases for the underlying update operation) if the target triple passed in is different from the host one, and prompt the user with target sub-commands in that case.

[mcandre]

Same error in Void Linux 3.7. I can install rustup via xbpx-install, but then when I actually try to install a toolchain, rustup complains that the musl target is missing.

[tooreht]

Same error in Void Linux 4.15. I can install rustup via xbpx-install, but then when I actually try to install a toolchain, rustup complains that the musl target is missing:

$ rustup override add nightly
info: syncing channel updates for 'nightly-x86_64-unknown-linux-musl'
260.7 KiB / 260.7 KiB (100 %)  19.4 KiB/s ETA:   0 s                
info: latest update on 2018-03-31, rust version 1.26.0-nightly (80785a547 2018-03-30)
error: target not found: 'x86_64-unknown-linux-musl'

[pickfire]

Rustup now will search for the last valid toolchain, is still still valid?