When `rustup update` fails, it doesn't return an exit code that indicate failure

[dzamlo]

Problem

When rustup update fails, it doesn't return an exit code that indicate failure but instead returns 0.

Steps

1. Be in a situation where rustup update fails, for example by disabling your network connection
2. Run rustup update
3. The command returns the exit code 0, or success

Possible Solution(s)

Return an exit code different than 0 in case of failure

Notes

No response

Rustup version

rustup 1.26.0 (2023-05-04)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.72.0 (5680fa18f 2023-08-23)`

Installed toolchains

Not relevant

[rami3l]

Thanks for @roife's confirmation: this issue doesn't seem to be reproducible with the official prebuilt binary, so this could be a specificity of the no-self-update feature.

[rami3l]

As a matter of fact, the following line (L295):

rustup/src/cli/common.rs

Lines 290 to 296 in 4149df6

	pub(crate) async fn update_all_channels(
	cfg: &Cfg<'_>,
	do_self_update: bool,
	force_update: bool,
	) -> Result<utils::ExitCode> {
	let toolchains = cfg.update_all_channels(force_update).await?;

... has muted all failures during the update, which is quite inappropriate.