Korp hangs in `subprocess.Popen` with gevent >= 25.8.1

[janiemi]

After the dependency updates in commit 0c3e046, my local Korp began to hang when responding a request. This happens with both the Flask dev server and gevent.

It seems to me that Korp hangs in the subprocess.Popen constructor called in korp.cwb.run_cqp. I then noticed that Korp doesn’t hang if you comment out the monkey-patching code in run.py, nor if you downgrade gevent from 25.9.1 to 25.5.1 (or earlier), so the problem would seem to be related to gevent.

I’m wondering if you have been able to run Korp with gevent 25.9.1 (as indicated by requirements.txt) or if this is somehow specific to our environment. If you have also encountered the problem, should it be reported to gevent? But if the problem only occurs in our environment, I’m wondering what could be the incompatible component or what else could cause it.

I have tested this with Python 3.10.19, 3.12.3 and 3.14.0 on Ubuntu 24.04.1. The same also happened with Python 3.9.21 on AlmaLinux 9.5 when running via Gunicorn.

[MartinHammarstedt]

You are right, I can confirm that we have the same problem here. I've been so focused on a new feature for the word picture that I hadn't actually tried to do any regular queries since updating the dependencies. I will have to investigate. Thanks for bringing it to my attention!

[MartinHammarstedt]

I've just pushed a commit which hopefully solves this problem. I have only done minimal testing so far, but it seems to work here. Could you please test it on your end as well, when you have time?