Workaround

I can’t reproduce this when the dev console is attached. You can open the dev console in one terminal using textual console and launch your app with textual run --dev <yourprogram.py> in order to (probably) work around this issue.

---

import json
from pathlib import Path

from rich.text import Text

from textual.app import App, ComposeResult
from textual.widgets import Header, Footer, Static

class TreeApp(App):

    BINDINGS = [
        ("a", "add", "Add node"),
    ]

    def compose(self) -> ComposeResult:
        yield Header()
        yield Footer()
        yield Static("Press A to crash")

    def action_add(self) -> None:
        raise Exception("This error should print")

if __name__ == "__main__":
    app = TreeApp()
    app.run()

Open app, press A, no output on stdout. Weirdly I did get stdout errors once or twice, so apologies for the heisenbug. If you can’t reproduce this I’ll try posting my frozen dependencies and all that.

# Textual Diagnostics

## Versions

| Name    | Value  |
|---------|--------|
| Textual | 0.14.0 |
| Rich    | 13.3.2 |

## Python

| Name           | Value                                                                                  |
|----------------|----------------------------------------------------------------------------------------|
| Version        | 3.10.9                                                                                 |
| Implementation | CPython                                                                                |
| Compiler       | GCC 12.2.0                                                                             |
| Executable     | /home/traverseda/.cache/pypoetry/virtualenvs/pyadminconsole-Ykr_Mx4S-py3.10/bin/python |

## Operating System

| Name    | Value                                                      |
|---------|------------------------------------------------------------|
| System  | Linux                                                      |
| Release | 6.2.2-zen1-1-zen                                           |
| Version | #1 ZEN SMP PREEMPT_DYNAMIC Fri, 03 Mar 2023 15:58:29 +0000 |

## Terminal

| Name                 | Value          |
|----------------------|----------------|
| Terminal Application | *Unknown*      |
| TERM                 | xterm-256color |
| COLORTERM            | truecolor      |
| FORCE_COLOR          | *Not set*      |
| NO_COLOR             | *Not set*      |

## Rich Console options

| Name           | Value                |
|----------------|----------------------|
| size           | width=236, height=55 |
| legacy_windows | False                |
| min_width      | 1                    |
| max_width      | 236                  |
| is_terminal    | True                 |
| encoding       | utf-8                |
| max_height     | 55                   |
| justify        | None                 |
| overflow       | None                 |
| no_wrap        | False                |
| highlight      | None                 |
| markup         | None                 |
| height         | None                 |