test_bash_integration fails with bash 5.2.0-release

[lcheylus]

Describe the bug
When I try to build Kitty v0.26.4 on Debian testing/amd64, test_bash_integration test fails with bash version 5.2.0-release

To Reproduce
Steps to reproduce the behavior:

1. Build kitty 0.26.4 with python3 setup.py build
2. Run tests with python3 setup.py test
3. See error

======================================================================
FAIL: test_bash_integration (kitty_tests.shell_integration.ShellIntegration)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fox/tmp/kitty-tmp/kitty/launcher/../../kitty_tests/shell_integration.py", line 372, in test_bash_integration
    self.ae(env.get('ES'), 'a\n `b` c\n$d', f'Screen contents: {pty.screen_contents()!r}')
    env = {'BASH_SILENCE_DEPRECATION_WARNING': '1', 'KITTY_INSTALLATION_DIR': '/home/fox/tmp/kitty-tmp', 'LANG': 'en_US.UTF-8', 'PATH': '/home/fox/tmp/kitty-tmp/kitty/launcher:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games', 'PYTHONDONTWRITEBYTECODE': '1', 'TERM': 'xterm-kitty', 'TERMINFO': '/home/fox/tmp/kitty-tmp/terminfo'}
    ps1 = 'line1\nprompt> '
    pty = <kitty_tests.PTY object at 0x7f0a48c32ad0>
    q = '/tmp/tmp5q9ttnai/testing-cwd-notification-🐱'
    redrawn = <function ShellIntegration.test_bash_integration.<locals>.redrawn at 0x7f0a451e3ac0>
    run_test = <function ShellIntegration.test_bash_integration.<locals>.run_test at 0x7f0a451e3b50>
    self = <kitty_tests.shell_integration.ShellIntegration testMethod=test_bash_integration>
    setup_env = <function ShellIntegration.test_bash_integration.<locals>.setup_env at 0x7f0a45164ca0>
AssertionError: None != 'a\n `b` c\n$d' : Screen contents: '[bash.bashrc]\nclone-in-kitty\nline1\nprompt> clone-in-kitty\nline1\nprompt> '

----------------------------------------------------------------------
Ran 140 tests in 6.792s

FAILED (failures=1, skipped=5)

Bash version is 5.2.0(1)-release :

$ bash --version
GNU bash, version 5.2.0(1)-release (x86_64-pc-linux-gnu)

[kovidgoyal]

dup of #5473

[lcheylus]

Sorry but it's not a duplicate of #5473 : my Bash release is an official one, not a RC with DEBUG enabled.

In comment #5473 (comment) you write that my output "[bash.bashrc]\nclone-in-kitty\nline1\nprompt> clone-in-kitty\nline1\nprompt>" is the expected one with a normal bash.

[kovidgoyal]

Ah OK, I saw debian testing and assumed it had DEBUG. When bash 5.2.0 comes to Arch I will investigate, dont have the time to build bash from source right now.

[jamessan]

Should this be left open, then?

[ctrlcctrlv]

I can confirm this is not a Debian packaging problem. Happens for me in the exact same way when I try to run tests with a Bash compiled from bash-5.2.9.tar.gz from the official gnu.org site.

[kovidgoyal]

IIRC kitty.bash doesn't use the DEBUG trap, in fact it doesnt use traps
at all.

[ctrlcctrlv]

Yeah I was wrong about that, deleted it 😅 but I know you tend to reply to emails, not look at the tracker. Sorry.

[ctrlcctrlv]

Here's something I'm more sure of...the shell integration doesn't seem to be working, not only the test, in Bash 5.2.

default syntax highlighter: pygmentize
fred@mapache:~/Workspace/kitty$ echo $KITTY_^V^V
$KITTY_INSTALLATION_DIR  $KITTY_PID               $KITTY_PUBLIC_KEY        $KITTY_WINDOW_ID         
fred@mapache:~/Workspace/kitty$ echo $KITTY_

Looking at the scripts, I think this test failure is legitimate: we can no longer read from the Bash environment in the way we're expecting.

Such that this happens:

fred@mapache:~/Workspace/kitty$ export KITTY_SHELL_INTEGRATION="enabled"
fred@mapache:~/Workspace/kitty$ echo $KITTY_SHELL_INTEGRATION 
enabled
fred@mapache:~/Workspace/kitty$ . ./shell-integration/bash/kitty.bash
fred@mapache:~/Workspace/kitty$ echo $KITTY_SHELL_INTEGRATION 

fred@mapache:~/Workspace/kitty$ 

[kovidgoyal]

kitty.bash explicitly unsets KITTY_SHELL_INTEGRATION that is not a sign
of shell integration not working.

[ctrlcctrlv]

How does Kitty get the env back from the subprocess?