BUG: DeprecationWarning: arg_id_to_dtype passed to InKernelCallable was not hashable

[c-abird]

I'm getting deprecation warnings for the interpolation of certain (not all) expressions. Minimal example:

import firedrake as fd
import warnings

warnings.simplefilter("always")

mesh = fd.UnitCubeMesh(1,1,1)
V = fd.FunctionSpace(mesh, "CG", 1)
x, y, z = fd.SpatialCoordinate(mesh)
fd.Function(V).interpolate(fd.sin(x))

results in output

/usr/lib/python3.12/dataclasses.py:1581: DeprecationWarning: arg_id_to_dtype passed to InKernelCallable was not hashable. This usage is deprecated and will stop working in 2026.
  return obj.__class__(**changes)
/usr/lib/python3.12/dataclasses.py:1581: DeprecationWarning: arg_id_to_descr passed to InKernelCallable was not hashable. This usage is deprecated and will stop working in 2026.
  return obj.__class__(**changes)

I'm using a fresh install of Firedrake on an Ubuntu 24.04 system.

[c-abird]

Is this maybe connected to #3821 ?

[connorjward]

This is actually an internal issue to loopy. I see the same warnings in their CI: https://github.com/inducer/loopy/actions/runs/13019796463/job/36317621215

[connorjward]

I've made an issue: inducer/loopy#905