Dask 2.26.0 breaks test_read_vcfzarr

[ravwojdyla]

dask was released yesterday version: 2.26.0 and it breaks our test_read_vcfzarr. That same test works fine on 2.25.0.

Originally posted by @ravwojdyla in https://github.com/pystatgen/sgkit/pull/228#issuecomment-691538352

The issue seems to be that:

    ds["variant_id_mask"] = (
        [DIM_VARIANT],
        variants_id == ".",
    )

returns (['variants'], False) instead of array of bool as the 2nd element.

[ravwojdyla]

Further:

import dask.array as da

a = da.from_array(["a", "b", ".", "e"])
print(a == ".")

# 2.26.0: False
# 2.25.0: dask.array<eq, shape=(4,), dtype=bool, chunksize=(4,), chunktype=numpy.ndarray>

That's a rather big change.

[ravwojdyla]

I have reported this as a bug in Dask (and will continue analysis there): dask/dask#6631

[ravwojdyla]

was fixed via #246 closing