Converter only applied when __post_init__ is defined for subclasses

[gorold]

I want to have the following inheritance structure, where subclasses only need to define a function to initialise the static fields, but encountered this unintuitive behavior, where the converter is only applied when __post_init__ is defined for the children.

Reproduce

import abc
import equinox as eqx
import jax
import jax.numpy as jnp


class A(eqx.Module):
    a: jax.Array = eqx.field(converter=jnp.asarray)
    b: int = eqx.field(init=False, static=True)

    def __post_init__(self):
        # do something here for all subclasses
        print(type(self.a))
        self.init_b()

    @abc.abstractmethod
    def init_b(self): ...
    
class B(A):
    def init_b(self):
        self.b = 1

class C(A):
    def __post_init__(self):
        super().__post_init__()

    def init_b(self):
        self.b = 1

b = B(0)
c = C(0)

Output

<class 'int'>
<class 'jaxlib.xla_extension.ArrayImpl'>

Expected Output

<class 'jaxlib.xla_extension.ArrayImpl'>
<class 'jaxlib.xla_extension.ArrayImpl'>