Feature suggestion: implicitly convert stderr to a String

[n-eq]

Hello,

In MergeError::ExternalToolError, stderr contain the error logs of the external tool. However, currently it's a Vec<u8>. For cases when there is an error it would be much more helpful for debugging to directly return the error as a string, using String::from_utf8.

Does this sound interesting to you? I can create a PR unless you want to work on it.

Thanks!

[tux3]

Hello, thanks for the suggestion, I think that's a good ergonomics improvement

I whipped up a branch quickly, let me know if that matches what you expected. I'm using from_utf8_lossy to avoid the failable case, but in practice this is for display, I don't think anyone will reasonably want to parse non-utf8 data from stdout/stderr

It's an API break, so requires a 2.0, but that's fine.

[n-eq]

Thanks for the effort, I just reviewed your PR.