refactor: add automatic conversion for nix::Errno

[orhun]

An attempt to fix #4007

[sylvestre]

it would be nice to test this :)
thanks

[sylvestre]

needs some comments here :)
and usage examples

[sylvestre]

see the function below

[orhun]

c19c19e

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/misc/tee is no longer failing!
GNU test failed: tests/misc/sync. tests/misc/sync is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/rm/rm2. tests/rm/rm2 is passing on 'main'. Maybe you have to rebase?

[tertsdiepraam]

Cool! This is exactly what I had in mind. I'd just like to have it implemented for nix::error (without being wrapped in a result) as well. (And I agree with Sylvestre's comments)

[orhun]

it would be nice to test this :)

How can I test it? Is adding usage examples as comments enough?

I'd just like to have it implemented for nix::error (without being wrapped in a result) as well.

Do you mean impl<T> FromIo<UResult<T>> for nix::Error or impl FromIo<UIoError> for nix::Error? Both are possible and I don't know which one is more convenient.

[tertsdiepraam]

How can I test it? Is adding usage examples as comments enough?

You could make a unit test that you know gives an error and assert that the error that you get is correct.

Do you mean impl<T> FromIo<UResult<T>> for nix::Error or impl FromIo<UIoError> for nix::Error? Both are possible and I don't know which one is more convenient.

The same as for std::io::Error. We map to Box<UIoError> because that's what goes into a UResult:

impl FromIo<Box<UIoError>> for std::io::Error {
    fn map_err_context(self, context: impl FnOnce() -> String) -> Box<UIoError> {
        Box::new(UIoError {
            context: Some((context)()),
            inner: self,
        })
    }
}
impl<T> FromIo<UResult<T>> for std::io::Result<T> {
    fn map_err_context(self, context: impl FnOnce() -> String) -> UResult<T> {
        self.map_err(|e| e.map_err_context(context) as Box<dyn UError>)
    }
}

These would also be nice to have for nix::error:

impl From<std::io::Error> for UIoError {
    fn from(f: std::io::Error) -> Self {
        Self {
            context: None,
            inner: f,
        }
    }
}
impl From<std::io::Error> for Box<dyn UError> {
    fn from(f: std::io::Error) -> Self {
        let u_error: UIoError = f.into();
        Box::new(u_error) as Self
    }
}

[sylvestre]

Could you please fix the clippy warning? thanks

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/sync. tests/misc/sync is passing on 'main'. Maybe you have to rebase?

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/sync. tests/misc/sync is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/tee. tests/misc/tee is passing on 'main'. Maybe you have to rebase?

[orhun]

I'm not sure why the CI is failing.

[orhun]

Friendly ping 🏓

[sylvestre]

Just rebased it. It had some job failures

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/misc/timeout is no longer failing!
GNU test failed: tests/misc/sync. tests/misc/sync is passing on 'main'. Maybe you have to rebase?

[sylvestre]

Could you please have a look to https://github.com/uutils/coreutils/actions/runs/3355920132/jobs/5560563514?

[sylvestre]

ping? :)

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/sync. tests/misc/sync is passing on 'main'. Maybe you have to rebase?

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/sync. tests/misc/sync is passing on 'main'. Maybe you have to rebase?

[orhun]

Still not sure why the CI is failing 🤔

[sylvestre]

you can ignore these :)