Intermittent hang in CI on textual-macOS testbed tests.

[freakboy3742]

Describe the bug

We are seeing an intermittent hang in the textual-macOS tests in CI.

The CI pass is terminated after 20 minutes; when the suite passes, it runs in under a minute.

How to reproduce the bug

Run the testbed test suite using the Textual backend under macOS.

Minimum example code

briefcase dev -a testbed-textual

Screenshots

No response

Environment details

• Operating system and version: macOS 15
• Python version: 3.12
• Software versions:
  • Toga: main as of July 17 2026

Logs

The test suite fails after the text input test_quote_dash_substitution_disabled tests:

tests/widgets/test_textinput.py::test_value_not_hidden PASSED            [ 81%]
tests/widgets/test_textinput.py::test_on_change_programmatic[True-] PASSED [ 82%]
tests/widgets/test_textinput.py::test_on_change_programmatic[True-placeholder] PASSED [ 83%]
tests/widgets/test_textinput.py::test_on_change_programmatic[False-] PASSED [ 83%]
tests/widgets/test_textinput.py::test_on_change_programmatic[False-placeholder] PASSED [ 84%]
tests/widgets/test_textinput.py::test_on_change_user PASSED              [ 85%]
tests/widgets/test_textinput.py::test_on_change_user_after_initial_value PASSED [ 85%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[""] PASSED [ 86%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[''] PASSED [ 87%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[--] PASSED [ 87%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[---] PASSED [ 88%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[Humorless "test" input] PASSED [ 89%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[Can't 'bee' bothered] PASSED [ 89%]
tests/widgets/test_textinput.py::test_quote_dash_substitution_disabled[Bee dashing--or fail miserably. --- No One Ever] PASSED [ 90%]
Error: The action 'Test App' has timed out after 20 minutes.

Additional context

No response