error_stack errors improperly parsed by rust-mode on emacs

[wildwestrom]

This is related to rust-lang/rust-mode#452.
I won't repost all the information from there.

Since trying to make rust-mode also parse this particular type of error seems a bit cumbersome, I think it may make sense to add a .dir-locals.el file that somebody can drop into their project.

[wildwestrom]

  (setq error_stack-regexps
    '("\\(?:at\\|',\\) \\(\\([^:\s]+\\):\\([0-9]+\\)\\)"
      2 3 nil nil 1))
  (setf (cdr (assoc 'cargo compilation-error-regexp-alist-alist))
        error_stack-regexps)

Here's my current workaround. I just need to figure out how to make this work locally only.
Of course, if it's not a problem for @rust-lang to add this to rust-mode then I won't have to consider this as an option.

[TimDiekmann]

Hi @wildwestrom and thanks for reporting this!

Would you like to open a PR for this? While this should be fixed in Emacs, we're happy to provide a temporary workaround until this is fixed to improve user performance.

[wildwestrom]

Would you like to open a PR for this?

Absolutely!
I'm thinking that since there is no way to make compilation-error-regexp-alist-alist a local variable, then I'll have to edit the list itself.
Maybe this can just be somewhere in documentation. What do you think?

[TimDiekmann]

I never used emacs so I'm probably the wrong one to ask if/how this is possible. Adding this to the README.md sounds reasonable I think!