TST: dask tests are extremely flaky

.github/workflows/array-api-tests-dask.yml

@@ -10,4 +10,5 @@ jobs:
       package-version: '>= 2024.9.0'
       module-name: dask.array
       extra-requires: numpy
-      pytest-extra-args: --disable-deadline --max-examples=5
+      # Remove thread synchronization overhead to speed up tests
+      extra-env-vars: DASK_SCHEDULER=sync

.github/workflows/array-api-tests.yml

@@ -33,7 +33,7 @@ on:
         description: "Multiline string of environment variables to set for the test run."
 
 env:
-  PYTEST_ARGS: "--max-examples 200 -v -rxXfE --ci ${{ inputs.pytest-extra-args }} --hypothesis-disable-deadline"
+  PYTEST_ARGS: "--max-examples 200 -v -rxXfE --ci ${{ inputs.pytest-extra-args }} --hypothesis-disable-deadline --durations 10"
 
 jobs:
   tests:

dask-skips.txt

@@ -1,5 +1,2 @@
-# slow and not implemented in dask
-array_api_tests/test_linalg.py::test_matrix_power
-
-# hangs on 2024.12
-array_api_tests/test_creation_functions.py::test_eye
+# Passes, but extremely slow
+array_api_tests/test_linalg.py::test_outer

dask-xfails.txt

@@ -1,3 +1,7 @@
+# Shape mismatch; needs high priority investigation
+array_api_tests/test_array_object.py::test_setitem
+array_api_tests/test_indexing_functions.py::test_take
+
 # Various indexing errors
 array_api_tests/test_array_object.py::test_getitem_masking
 
@@ -85,32 +89,24 @@ array_api_tests/test_has_names.py::test_has_names[array_method-__dlpack_device__
 # No mT on dask array
 array_api_tests/meta/test_hypothesis_helpers.py::test_symmetric_matrices
 
-# Edge case of args near 2**63
-# https://github.com/dask/dask/issues/11706
-array_api_tests/test_creation_functions.py::test_arange
+# da.searchsorted with a sorter argument is not supported
+array_api_tests/test_searching_functions.py::test_searchsorted
 
 # 2023.12 support
 array_api_tests/test_manipulation_functions.py::test_repeat
 
 # 2024.12 support
-array_api_tests/test_array_object.py::test_setitem
 array_api_tests/test_array_object.py::test_getitem_arrays_and_ints_1[1]
 array_api_tests/test_array_object.py::test_getitem_arrays_and_ints_1[None]
 array_api_tests/test_array_object.py::test_getitem_arrays_and_ints_2[1]
 array_api_tests/test_array_object.py::test_getitem_arrays_and_ints_2[None]
 array_api_tests/test_has_names.py::test_has_names[indexing-take_along_axis]
 array_api_tests/test_signatures.py::test_func_signature[take_along_axis]
-
 array_api_tests/test_linalg.py::test_cholesky
 array_api_tests/test_linalg.py::test_linalg_matmul
+array_api_tests/test_linalg.py::test_matmul
 array_api_tests/test_linalg.py::test_matrix_norm
 array_api_tests/test_linalg.py::test_qr
-array_api_tests/test_manipulation_functions.py::test_concat
-array_api_tests/test_manipulation_functions.py::test_roll
-array_api_tests/test_operators_and_elementwise_functions.py::test_add[add(x1, x2)]
-array_api_tests/test_operators_and_elementwise_functions.py::test_bitwise_left_shift[bitwise_left_shift(x1, x2)]
-array_api_tests/test_operators_and_elementwise_functions.py::test_bitwise_right_shift[bitwise_right_shift(x1, x2)]
-array_api_tests/test_operators_and_elementwise_functions.py::test_greater[__gt__(x1, x2)]
 array_api_tests/test_signatures.py::test_func_signature[count_nonzero]
 array_api_tests/test_special_cases.py::test_binary[floor_divide(x1_i is +infinity and isfinite(x2_i) and x2_i > 0) -> +infinity]
 array_api_tests/test_special_cases.py::test_binary[floor_divide(x1_i is +infinity and isfinite(x2_i) and x2_i < 0) -> -infinity]
@@ -131,5 +127,3 @@ array_api_tests/test_special_cases.py::test_iop[__ifloordiv__(x1_i is -infinity
 array_api_tests/test_special_cases.py::test_iop[__ifloordiv__(isfinite(x1_i) and x1_i > 0 and x2_i is -infinity) -> -0]
 array_api_tests/test_special_cases.py::test_iop[__ifloordiv__(isfinite(x1_i) and x1_i < 0 and x2_i is +infinity) -> -0]
 array_api_tests/test_special_cases.py::test_nan_propagation[cumulative_prod]
-
-