Jail::expect_with/try_with do not allow returning non-Figment Error types

[detjensrobert]

I am using Jails to set test config values and envvars for some tests, and the functions being tested all return a non-Figment Error type as a Result. The Jail body does not accept these errors as a valid return, and I have to either manually assert is_ok() or map the error into a String for every Result.

an example:

Ideally, the Jail body should accept something like Box<dyn Error> so that any application errors can be handled by early-?.

    figment::Jail::expect_with(|jail| {
        // would be ideal, but doesnt work
        fallible_foo()?;

        // works but gross
       breakable_bar().map_err(|e| format!("{e:?}"))?;

        Ok(())
    });