Mysterious and intermittent test failures

[Michael-T-McCann]

We have had occasional test failures: https://github.com/lanl/scico/runs/5062268572?check_suite_focus=true, https://github.com/lanl/scico/runs/5078490742?check_suite_focus=true

These involve scico/test/test_functional.py, and specifically scico/test/test_functional.py::TestNormProx::test_prox[float32-0.01-NuclearNorm] and scico/test/linop/test_optics.py::TestPropagator::test_prop_adjoint[FraunhoferPropagator-1]`. Search the very long stack trace for "typeerror:" to see what I think is the actual error.

[Michael-T-McCann]

Minimal code to reproduce. In the file temp_svd.py, put

import jax
import jax.numpy as jnp


def test():
    key = jax.random.PRNGKey(3)
    v = jax.random.normal(shape=(32, 1), key=key)

    svdU, svdS, svdV = jnp.linalg.svd(v, full_matrices=False)
    x = svdU @ jnp.diag(svdS) @ svdV
    sigma = jnp.linalg.svd(x, compute_uv=False)
    assert len(sigma) == 1

test()

then try

while python temp_svd.py
do
:
done

and wait. On my machine, you get a failure eventually, say within 100 iterations.

[Michael-T-McCann]

I have opened an issue with jax team on this: google/jax#9483

[Michael-T-McCann]

When/if this gets fixed on jax's side, let's revisit (probably roll back) #214.

[Michael-T-McCann]

Revert the changes.