Make it compatible with Free Threading (aka no-gil)

[thepabloaguilar]

Since Python 3.14 the no-gil feature is not experimental anymore but optional, when some of the dependencies are not marked that can run safely in those versions Python interpreter fallback to the default mode with GIL. This can impact when running on production but also when running tests:

<frozen importlib._bootstrap>:491: RuntimeWarning: The global interpreter lock (GIL) has been enabled to load module 'grimp._rustgrimp', which has not declared that it can run safely without the GIL. To override this behavior and keep the GIL disabled (at your own risk), run with PYTHON_GIL=0 or -Xgil=0.

It would be nice if this lib could be compatible with no-gil, if needed I can try to help!

[seddonym]

Thanks for the issue, I would like to support free threading but am not sure what is involved or how much work it is.

Any input on that welcome!

[thepabloaguilar]

We may want to add a test like this later:

import sys
import sysconfig

# Just importing should be enough for the test
import grimp

# it should only run for Python 3.14t+
def test_ensure_disabled_gil():
    assert sysconfig.get_config_var("Py_GIL_DISABLED") == 1:
    assert sys._is_gil_enabled() is False

Source: Identifying free-threaded Python

[thepabloaguilar]

Other interesting resources:

• Supporting Free-Threaded CPython
• Python Free-Threading Guide