opt(err): show renaming file error source

[Binlogo]

Problem you are trying to solve

We occasionally encounter the following error:

error: component download failed for cargo-aarch64-apple-darwin: could not rename downloaded file from '/Users/xxx/.rustup/downloads/344e710d......76ee75be1fff0c7bf3.partial' to '/Users/xxx/.rustup/downloads/344e710d......76ee75be1fff0c7bf3'

This issue is difficult to reproduce, so it's important to add a source for reporting first.

Description

This pull request introduces a RenamingFile error with a source to improve error handling for file renaming operations in the RustupError enum. It updates the codebase to use this new error type, enhancing the clarity and consistency of error reporting.

[djc]

Should the std::error::Error::source() method be implemented to yield the source error for this?

[Binlogo]

Should the std::error::Error::source() method be implemented to provide the source error for this?

@djc Thanks for asking, but I'm not sure, actually. I noticed that SettingPermissions is using io::Error here, so I followed the same pattern. Do you have any suggestions?

[Binlogo]

Should the std::error::Error::source() method be implemented to yield the source error for this?

According to the thiserror documentation, it states:

The Error trait’s source() method is implemented to return whichever field has a #[source] attribute or is named source, if any. This is for identifying the underlying lower level error that caused your error.

The #[from] attribute always implies that the same field is #[source], so you don’t ever need to specify both attributes.

Any error type that implements std::error::Error or dereferences to dyn std::error::Error will work as a source.

#[derive(Error, Debug)]
pub struct MyError {
    msg: String,
    #[source]  // optional if field name is `source`
    source: anyhow::Error,
}

Is it still necessary to implement the std::error::Error::source() method?

[djc]

Sure, but your PR does not add any #[source] attribute, right?

[Binlogo]

Sure, but your PR doesn't add any #[source] attribute, right?

This PR didn't add #[source] because this macro is optional if the field name is source, as the documentation mentions.

So it should implemented std::error::Error::source() method by thiserror crate.

[djc]

Sure, but your PR doesn't add any #[source] attribute, right?

This PR didn't add #[source] because this macro is optional if the field name is source, as the documentation mentions.

So it should implemented std::error::Error::source() method by thiserror crate.

Ahh, okay, thanks.

[rami3l]

Looks nice to me, thanks!

@djc Do you happen to have remaining concerns or all of them have been addressed already?

[djc]

@Binlogo just squash your commits please -- the second commit really belongs with the first one.

[Binlogo]

@djc Squashed. Thanks for the review.