(The above debci log is misleading due to #764081; pocl also changed,
and the failure goes away on using the old pocl.)
It looks like this fails because it is reading the result before the
computation has finished:
- On a failure, the np.asarray(gr) passed to assert_allclose doesn't
match cr (hence the fail), but np.asarray(gr) run manually from the
debugger (i.e. later) does match cr.
- Adding a time.sleep(0.1) to the test stops that test failing.
- Which tests fail varies from run to run.
I don't yet know if this is pocl's or libgpuarray's fault.
