Display path where error "Could not create archive" occurred

[GabrielSimonetto]

While working on #94 we wound up wanting to build better errors for some cases, one of them is this FinalError:

builder.append_file(path, file.file_mut()).map_err(|err| {
    FinalError::with_title("Could not create archive")
        .detail("Unexpected error while trying to read file")
        .detail(format!("Error: {}.", err))
        .into_owned()
})?;

It isn't a great error message since it doesn't tell you which file broke, in a scenario where you are compressing/decompressing multiple files this could be an issue.

Now, it is troublesome to insert the output_file, since it was inserted on the tar writer from it's generic call. This is a problem because:

• It seems that the Writer object does not have a getter to the output_path where it intends to write stuff, so we can't get this information from it.
• So we would end up trying to pass output_path on the function? Maybe, but since it's a generic call we would need to reproduce it to the zip call aswell I think.

So... I can't see a clear path of action, and this is already a hard error to occur aswell, therefore I will put the discussion tag and the low-priority one

[marcospb19]

Just stopped to think about it, and we don't give this amount of context info when compressing with zip too.

And there are multiple points in that source code where errors can appear, so I guess we need to put custom error messages outside of both calls.

Maybe one message will do it for both, Failed to create the archive {}, fits for zip and tar.

What do you think?

[GabrielSimonetto]

That sounds ideal, you're saying that if the error breaks inside tar or zip modules, it can propagate the error upwards and then the calling method can finish annotating context? I like that