Scalar ODEs on Windows failing because of a casting & broadcastability issue that was fixed only for Linux

[michaelosthege]

Description of your problem

Three ODE tests - all testing with a scalar ODE - still run into broadcastability problems.
The related Aesara ticket aesara-devs/aesara#390 was closed with a fix that did fix the aforementioned tests for non-Windows OSes.

But the tests kept failing for Windows, so apparently the issue still persists under some rare circumstances.

Also see #4902 which edited the @pytest.mark.xfail conditions accordingly.

Versions and main components

• PyMC3 Version: main
• Aesara Version: 2.1.3
• Operating system: Windows

[ricardoV94]

Figured out the source of difference in behavior. Aesara constant integer lists have dtype int32 in Windows but dtype int64 in Linux.

import aesara.tensor as at

# Changes from int64 in Linux to int32 in Windows
print(at.constant([1]).dtype)

This leads to an extra casting in the size input when creating RVs in Windows compared to Linux.

# Will be a constant in Linux but a SpecifyShape of a cast in Windows
print(at.random.normal(size=[1]).owner.inputs[1])

Which might lead to further issues down the road due to things like aesara-devs/aesara#692