Python OverflowError : in method 'get_GDSII_prisms', argument 3 of type 'int'

Question

I'm a new user of a Python module called meep. I followed this tutorial and everything works fine. However, I tried to change something and I keep having the same error : OverflowError : in method 'get_GDSII_prisms', argument 3 of type 'int'

Here is the part of the code that causes trouble :

gdsII_file = 'coupler.gds'
UPPER_BRANCH_LAYER = 31
si_zmax = 10
si_zmin = -10

def test(p):
    return mp.Medium(index=15)
    
upper_branch = mp.get_GDSII_prisms(test, gdsII_file, UPPER_BRANCH_LAYER, si_zmin, si_zmax)

The only change I made is that I put a function as first argument of get_GDSII_prisms instead of a mp.Medium instance (calling mp.get_GDSII_prisms(mp.Medium(index=15), gdsII_file, UPPER_BRANCH_LAYER, si_zmin, si_zmax doesn't create any trouble.) But this should work since every function of this module that takes a mp.Medium instance can also take a user-defined function. Moreover, I found it strange that Python finds an error on argument 3 whereas I only changed argument 1.

I looked on the internet in order to understand why I have this error and how to resolve it but I didn't found anything.

I'm using Python 3.8.5.

Thank you for your help!