Closes#45211
This ensures that all sub-processes that were launched by the ACP server
are terminated. One scenario where this is easily reproducible:
- Start a new Claude Code ACP session
- Submit a prompt
- While Claude-code is still responding, start a new session
- The `claude-code` subprocess is leaked from the previous session (The
Claude-code SDK runs the Claude-code binary in a sub process)
This PR fixes this by using process groups on Unix.
It does not fix the process leaks on Windows yet (will follow up with
another PR)
Release Notes:
- Fixed an issue where subprocesses of ACP servers could be leaked after
starting a new session
Using `shlex` unconditionally is dangerous as it assumes the underlying
shell is POSIX which is not the case for PowerShell, CMD, or Nushell.
Therefore, whenever we want to quote the args we should utilise our
helper `util::shell::ShellKind::try_quote` which takes into account
which shell is being used to actually exec/spawn the invocation.
Release Notes:
- N/A
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Co-authored-by: Lukas Wirth <me@lukaswirth.dev>
Bennet Bo Fenner