fix: forward kill signals from pixi to deno task shell commands

[wolfv]

We had some logic that ignored CTRL+C on the pixi level. However, my understanding is that it only made CTRL+C "transparent" so that it reached the right process underneath, but didn't properly set up forwarding for CTRL+C and other signals.

By using the KillSignal from deno_task_shell we can properly forward any signal received in pixi to the child processes.

Should fix #3789

TODO:

• check that CTRL+C works on all platforms (currently only tested on macOS)
• check that CTRL+C in selection dialog still looks good

[baszalmstra]

If this works that would be great! Lets test it throughly!

[baszalmstra]

Isnt this still an issue?

[baszalmstra]

Is this used?

[baszalmstra]

deno?

[baszalmstra]

Please remove commented code.

[ruben-arts]

Using the example in the issue this doesn't allow me to correctly stop the pixi process anymore.

import signal
import time

def signal_handler(signum, frame):
    print(f"Signal handler called with signal {signum}")

signal.signal(signal.SIGINT, signal_handler)

while True:
    time.sleep(1)

This will run indefinitely without me being able to stop it. While the old pixi allows me to send ctrl+z to suspend it.

If I add exit(0) to the signal_handler it gives me this output:

➜ pixi run python test.py
^CSignal handler called with signal 2
Traceback (most recent call last):
 File "/Users/rubenarts/dev/pixi/test.py", line 11, in <module>
   time.sleep(1)
   ~~~~~~~~~~^^^
 File "/Users/rubenarts/dev/pixi/test.py", line 5, in signal_handler
   print(f"Signal handler called with signal {signum}")
   ~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 File "/Users/rubenarts/dev/pixi/test.py", line 5, in signal_handler
   print(f"Signal handler called with signal {signum}")
   ~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: reentrant call inside <_io.BufferedWriter name='<stdout>'>

❯

While the latest release gives me:

➜  ~/.pixi/bin/pixi run python test.py
^CSignal handler called with signal 2
➜ 

[wolfv]

Thanks for trying. Indeed, I also added exit(0) inside the signal handler to make it actually stop. I haven't tested on Linux yet, but looks like that might be necessary.

[wolfv]

When I run this, I get:

╭─wolfv@pixi ~/Programs/pixi/examples/ctrlc ‹use-kill-signal●› 
╰─$ cargo r -- run python test.py                                                                           1 ↵
   Compiling pixi v0.47.0 (/Users/wolfv/Programs/pixi)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 14.50s
     Running `/Users/wolfv/Programs/pixi/target/debug/pixi run python test.py`
Sleeping...
Sleeping...
^CSignal handler called with signal 2

[ruben-arts]

The problem for me is that I can't properly quit it when the signal is ignored by the running executable. Pixi just sends it through and doesn't stop.