[BUG] 'Point' object layout differs from 'Point'

[jeertmans]

Reposted message from @gdambic.

Discussed in #91

^{Originally posted by gdambic November 28, 2024}
Hello,

I get an error when trying to use a simple scene and I am not sure what I am doing wrong. Here are the steps to reproduce:

1. Create a new venv, Python 3.12
2. Install differt2d: pip install differt2d
3. Add code:

from differt2d.scene import Scene
scene = Scene.square_scene()

When run, I get:

C:\path\.venv\Scripts\python.exe C:\path\main.py 
Traceback (most recent call last):
  File "C:\path\main.py", line 3, in <module>
    scene = Scene.square_scene()
            ^^^^^^^^^^^^^^^^^^^^
  File "C:\path\.venv\Lib\site-packages\differt2d\scene.py", line 742, in square_scene
    tx = Point(xy=jnp.asarray(tx_coords, dtype=float))
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\path\.venv\Lib\site-packages\equinox\_module.py", line 594, in __call__
    object.__setattr__(self, "__class__", cls)
TypeError: __class__ assignment: 'Point' object layout differs from 'Point'

What am I doing wrong?

[jeertmans]

Hi @gdambic, could you provide information of your local Python environment? I will try to reproduce this myself locally.

[gdambic]

Hi, @jeertmans,
thank you for your quick reply!
I use PyCharm 2024.1 (Community Edition):

Build #PC-241.14494.241, built on March 28, 2024
Runtime version: 17.0.10+8-b1207.12 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Windows 10.0
GC: G1 Young Generation, G1 Old Generation
Memory: 4068M
Cores: 12
Registry: ide.experimental.ui=true

I use Python 3.12.2 as the interpreter, with a dedicated virtualenv for the project. I only installed "pip install differt2d" and it installed the following dependencies:

absl-py==2.1.0
beartype==0.19.0
chex==0.1.87
contourpy==1.3.1
cycler==0.12.1
differt-core==0.0.17
DiffeRT2d==0.3.4
equinox==0.11.9
etils==1.11.0
fonttools==4.55.0
jax==0.4.35
jaxlib==0.4.35
jaxtyping==0.2.36
kiwisolver==1.4.7
matplotlib==3.9.2
ml_dtypes==0.5.0
numpy==2.1.3
opt_einsum==3.4.0
optax==0.2.4
packaging==24.2
pillow==11.0.0
pyparsing==3.2.0
python-dateutil==2.9.0.post0
scipy==1.14.1
setuptools==75.6.0
six==1.16.0
toolz==1.0.0
typing_extensions==4.12.2

Please let me know if you need any more info.

Thank you so much,
Goran

[jeertmans]

Thanks! I managed to reproduce the bug, and it looks like one of the upstream dependencies decided to change how class inheritance work. I fixed this in #93, and will hopefully merge and release this soon if the CI is happy :-)

[jeertmans]

Hi @gdambic, can you check that installing differt2d==0.3.5 fixes your issue?