[bug]: Shutdown is hanging on a thread lock

[lstein]

Is there an existing issue for this problem?

• I have searched the existing issues

Install method

Invoke's Launcher

Operating system

Linux

GPU vendor

Nvidia (CUDA)

GPU model

No response

GPU VRAM

No response

Version number

lstein/feature/nicer-shutdown

Browser

No response

System Information

No response

What happened

After generating an image I tried to shut down the invokeai server by pressing ^C. It printed "InvokeAI shutting down..." and then hung indefinitely. I hit ^C again and it exited after printing a warning message about lock.acquire().

Here is the log:

^C
[2026-03-01 21:52:51,384]::[ModelInstallService]::INFO --> Installer thread 138019081299648 exiting
[2026-03-01 21:52:52,388]::[InvokeAI]::INFO --> InvokeAI shutting down...

^C
Exception ignored in: <module 'threading' from '/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/threading.py'>
Traceback (most recent call last):
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/threading.py", line 1624, in _shutdown
    lock.acquire()
KeyboardInterrupt: 

What you expected to happen

I expect InvokeAI to shut down on its own soon after the "shutting down..." message. I suspect that there is a thread somewhere that is holding onto a lock.

How to reproduce the problem

No response

Additional context

No response

Discord username

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