when waiting for output, and the process ends, it should show an error message

[kevgo]

Scenario: a long-running process crashes
  Given a file "1.md" with content:
    """
    <a textrun="start-console-command">
    ```
    $ crashing-process
    ```
    """
  When running text-run
  Then I see the error:
    | FILE  | 1.md                    |
    | LINE  | 1                       |
    | ERROR | the process has crashed |