VSCode / Swift / Codex Deadlock

What version of the Codex App are you using (From “About Codex” dialog)?

26.224.1209 (697)

What subscription do you have?

Plus

What platform is your computer?

26.3 (25D125) / Darwin 25.3.0 arm64 arm

What issue are you seeing?

This is a problem that happens on macOS with VSCode and the swift plugin.

The problem is that as soon as code changes, the VSCode/Swift-plugin combination will kick off a new build.

If Codex then tries to run swift build or swift test, it will hit the standard Swift message saying "Another instance of SwiftPM (PID: 19511) is already running ... waiting until that process has finished execution...".

That ought to be ok, but somehow it periodically manages to trigger the same state inside VSCode.

This leaves both Codex and VSCode/Swift-plugin deadlocked waiting for the other one to finish.

Responsibility is likely shared for this problem, but it would be good if Codex was aware of the possibility, and could mitigate against it in some way. For example by timing out and retrying its swift command if it spots a likely deadlock.

I can see that this might be someone else's bug, but the interactions with Codex are the only time I've ever seen this kind of thing resolve in a deadlock. Normally another process wins, finishes its swift command, and then the waiting command resumes.

What steps can reproduce the bug?

Open a SwiftPM project in VSCode, with the official Swift plugin installed.

Open the same project in the Codex app.

Ask Codex to perform an action that will result in a code change, and then in Codex trying to run swift build or swift test

What is the expected behavior?

Ideally the commands should just succeed. If Codex does hit a message about another process building, it should successfully wait for that to succeed, and then its own command(s) should succeed.

Additional information

_No response_