Cargo-process does not accept user input

Question

Using the Emacs mode for Cargo, I'm able to build and run Rust code inside Emacs. However, the terminal that opens when executing cargo-process-run does not accept user input.

For example, when running

use std::io;
fn main() {
  let mut input = String::new();

  io::stdin()
      .read_line(&mut input)
      .expect("Failed to read line.");
}

the terminal will hang without being capable of receiving keyboard input.

I've read that a similar problem can occur when executing compile, but this could somehow be resolved by starting in comint-mode. Unfortunately, I have not found a way to translate that solution to this scenario.

How can I resolve this?

Safron · Accepted Answer · 2019-06-22T19:40:17.063

3

After some research, I was able to solve it by adding this to my init.el:

(with-eval-after-load 'rust-mode
  (define-key rust-mode-map (kbd "C-r") 'my-cargo-run))
(defun my-cargo-run ()
  "Build and run Rust code."
  (interactive)
  (cargo-process-run)
  (let (
      (orig-win (selected-window))
      (run-win (display-buffer (get-buffer "*Cargo Run*") nil 'visible))
    )
    (select-window run-win)
    (comint-mode)
    (read-only-mode 0)
    (select-window orig-win)
  )
)

The function my-cargo-run calls cargo-process-run, enables comint-mode and disables the read-only mode of the terminal. The first two lines bind the function to C-r.

I've asked the author of cargo.el to include this in the package.

edited Jun 22 '19 at 19:40

answered Jun 22 '19 at 19:31

Safron

171
7

Thanks, very helpful. For `rustic-mode` changing `(cargo-process-run)` to `(rustic-cargo-run)` is enough. – Günter Zöchbauer Jun 29 '20 at 07:54
@Safron, is there some entry in an issue tracker for that? It's been a couple years and I don't see it in `cargo.el` yet. – daveloyall Jul 22 '22 at 22:20
@daveloyall It is tracked by https://github.com/kwrooijen/cargo.el/issues/29. No progress yet though... – Safron Jul 23 '22 at 09:56

bertfred · Answer 2 · 2020-07-04T09:00:26.687

1

Another possibility:

(defun rust-compile-send-input ()
  "Read string from minibuffer and send it to the rust process of the current
buffer."
  (interactive)
  (let ((input (read-from-minibuffer "Send input to rust process: "))
        (proc (get-buffer-process (current-buffer)))
        (inhibit-read-only t))
    (process-send-string proc (concat input "\n"))))

edited Jul 04 '20 at 09:00

answered Jul 03 '20 at 20:47

bertfred

1,699
1
11
23

Cargo-process does not accept user input

2 Answers2