ValueError: no signature found for builtin function <built-in function issubclass>

[smarie]

from funcsigs import signature
from functools import partial
f = partial(issubclass, bool)
signature(f)

yields

Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "C:\Miniconda3\envs\tools_py2\lib\site-packages\funcsigs\__init__.py", line 108, in signature
    sig = signature(obj.func)
  File "C:\Miniconda3\envs\tools_py2\lib\site-packages\funcsigs\__init__.py", line 185, in signature
    raise ValueError(msg)
ValueError: no signature found for builtin function <built-in function issubclass>

[smarie]

ok I saw in the doc that this might be normal.