CI: failing numpy_dev build on 1.2.x
this is passing on master, but not on 1.2.1

https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=52437&view=logs&j=eab14f69-13b6-5db7-daeb-7b778629410b&t=ce687173-08c6-5301-838d-71b2dda24510

```
2021-01-16T02:31:05.2414654Z =================================== FAILURES ===================================
2021-01-16T02:31:05.2415844Z _ TestComparison.test_index_series_compat[eq-IntervalIndex-array-assert_numpy_array_equal] _
2021-01-16T02:31:05.2416708Z [gw1] linux -- Python 3.8.5 /home/vsts/miniconda3/envs/pandas-dev/bin/python
2021-01-16T02:31:05.2417059Z 
2021-01-16T02:31:05.2417505Z self = <pandas.tests.arithmetic.test_interval.TestComparison object at 0x7f7984759fa0>
2021-01-16T02:31:05.2420975Z op = <built-in function eq>
2021-01-16T02:31:05.2447033Z constructor = <class 'pandas.core.indexes.interval.IntervalIndex'>
2021-01-16T02:31:05.2461011Z expected_type = <built-in function array>
2021-01-16T02:31:05.2461472Z assert_func = <function assert_numpy_array_equal at 0x7f79d19fb280>
2021-01-16T02:31:05.2461911Z 
2021-01-16T02:31:05.2462190Z     @pytest.mark.parametrize(
2021-01-16T02:31:05.2462598Z         "constructor, expected_type, assert_func",
2021-01-16T02:31:05.2462923Z         [
2021-01-16T02:31:05.2463268Z             (IntervalIndex, np.array, tm.assert_numpy_array_equal),
2021-01-16T02:31:05.2463755Z             (Series, Series, tm.assert_series_equal),
2021-01-16T02:31:05.2464080Z         ],
2021-01-16T02:31:05.2464384Z     )
2021-01-16T02:31:05.2464794Z     def test_index_series_compat(self, op, constructor, expected_type, assert_func):
2021-01-16T02:31:05.2465386Z         # IntervalIndex/Series that rely on IntervalArray for comparisons
2021-01-16T02:31:05.2465772Z         breaks = range(4)
2021-01-16T02:31:05.2466225Z         index = constructor(IntervalIndex.from_breaks(breaks))
2021-01-16T02:31:05.2466569Z     
2021-01-16T02:31:05.2466845Z         # scalar comparisons
2021-01-16T02:31:05.2467209Z         other = index[0]
2021-01-16T02:31:05.2467523Z         result = op(index, other)
2021-01-16T02:31:05.2467991Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2468402Z         assert_func(result, expected)
2021-01-16T02:31:05.2468765Z     
2021-01-16T02:31:05.2469036Z         other = breaks[0]
2021-01-16T02:31:05.2469532Z         result = op(index, other)
2021-01-16T02:31:05.2469988Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2470394Z         assert_func(result, expected)
2021-01-16T02:31:05.2470739Z     
2021-01-16T02:31:05.2471260Z         # list-like comparisons
2021-01-16T02:31:05.2471642Z         other = IntervalArray.from_breaks(breaks)
2021-01-16T02:31:05.2472056Z         result = op(index, other)
2021-01-16T02:31:05.2472452Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2472923Z         assert_func(result, expected)
2021-01-16T02:31:05.2473207Z     
2021-01-16T02:31:05.2473879Z         other = [index[0], breaks[0], "foo"]
2021-01-16T02:31:05.2474269Z         result = op(index, other)
2021-01-16T02:31:05.2474668Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2475135Z >       assert_func(result, expected)
2021-01-16T02:31:05.2475399Z 
2021-01-16T02:31:05.2475764Z pandas/tests/arithmetic/test_interval.py:287: 
2021-01-16T02:31:05.2476208Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2021-01-16T02:31:05.2476557Z 
2021-01-16T02:31:05.2476986Z left = array([False, False, False]), right = array([ True, False, False])
2021-01-16T02:31:05.2477357Z err_msg = None
2021-01-16T02:31:05.2477641Z 
2021-01-16T02:31:05.2477946Z     def _raise(left, right, err_msg):
2021-01-16T02:31:05.2478307Z         if err_msg is None:
2021-01-16T02:31:05.2478738Z             if left.shape != right.shape:
2021-01-16T02:31:05.2479107Z                 raise_assert_detail(
2021-01-16T02:31:05.2479563Z                     obj, f"{obj} shapes are different", left.shape, right.shape
2021-01-16T02:31:05.2479942Z                 )
2021-01-16T02:31:05.2480247Z     
2021-01-16T02:31:05.2480506Z             diff = 0
2021-01-16T02:31:05.2480879Z             for left_arr, right_arr in zip(left, right):
2021-01-16T02:31:05.2481340Z                 # count up differences
2021-01-16T02:31:05.2481806Z                 if not array_equivalent(left_arr, right_arr, strict_nan=strict_nan):
2021-01-16T02:31:05.2482323Z                     diff += 1
2021-01-16T02:31:05.2482597Z     
2021-01-16T02:31:05.2482891Z             diff = diff * 100.0 / left.size
2021-01-16T02:31:05.2483349Z             msg = f"{obj} values are different ({np.round(diff, 5)} %)"
2021-01-16T02:31:05.2483814Z >           raise_assert_detail(obj, msg, left, right, index_values=index_values)
2021-01-16T02:31:05.2484450Z E           AssertionError: numpy array are different
2021-01-16T02:31:05.2484795Z E           
2021-01-16T02:31:05.2485284Z E           numpy array values are different (33.33333 %)
2021-01-16T02:31:05.2485649Z E           [left]:  [False, False, False]
2021-01-16T02:31:05.2486175Z E           [right]: [True, False, False]
2021-01-16T02:31:05.2486482Z 
2021-01-16T02:31:05.2486757Z pandas/_testing.py:1159: AssertionError
2021-01-16T02:31:05.2487496Z _ TestComparison.test_index_series_compat[eq-Series-Series-assert_series_equal] _
2021-01-16T02:31:05.2488191Z [gw1] linux -- Python 3.8.5 /home/vsts/miniconda3/envs/pandas-dev/bin/python
2021-01-16T02:31:05.2488567Z 
2021-01-16T02:31:05.2488904Z self = <pandas.tests.arithmetic.test_interval.TestComparison object at 0x7f79840c7730>
2021-01-16T02:31:05.2489563Z op = <built-in function eq>, constructor = <class 'pandas.core.series.Series'>
2021-01-16T02:31:05.2490223Z expected_type = <class 'pandas.core.series.Series'>
2021-01-16T02:31:05.2490622Z assert_func = <function assert_series_equal at 0x7f79d19fb3a0>
2021-01-16T02:31:05.2490958Z 
2021-01-16T02:31:05.2491206Z     @pytest.mark.parametrize(
2021-01-16T02:31:05.2491526Z         "constructor, expected_type, assert_func",
2021-01-16T02:31:05.2491885Z         [
2021-01-16T02:31:05.2492201Z             (IntervalIndex, np.array, tm.assert_numpy_array_equal),
2021-01-16T02:31:05.2492660Z             (Series, Series, tm.assert_series_equal),
2021-01-16T02:31:05.2492958Z         ],
2021-01-16T02:31:05.2493334Z     )
2021-01-16T02:31:05.2493713Z     def test_index_series_compat(self, op, constructor, expected_type, assert_func):
2021-01-16T02:31:05.2494196Z         # IntervalIndex/Series that rely on IntervalArray for comparisons
2021-01-16T02:31:05.2494601Z         breaks = range(4)
2021-01-16T02:31:05.2515866Z         index = constructor(IntervalIndex.from_breaks(breaks))
2021-01-16T02:31:05.2516454Z     
2021-01-16T02:31:05.2516755Z         # scalar comparisons
2021-01-16T02:31:05.2517121Z         other = index[0]
2021-01-16T02:31:05.2517451Z         result = op(index, other)
2021-01-16T02:31:05.2518053Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2518530Z         assert_func(result, expected)
2021-01-16T02:31:05.2518818Z     
2021-01-16T02:31:05.2519159Z         other = breaks[0]
2021-01-16T02:31:05.2519477Z         result = op(index, other)
2021-01-16T02:31:05.2519960Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2520457Z         assert_func(result, expected)
2021-01-16T02:31:05.2520751Z     
2021-01-16T02:31:05.2521443Z         # list-like comparisons
2021-01-16T02:31:05.2521826Z         other = IntervalArray.from_breaks(breaks)
2021-01-16T02:31:05.2522244Z         result = op(index, other)
2021-01-16T02:31:05.2522645Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2523109Z         assert_func(result, expected)
2021-01-16T02:31:05.2523399Z     
2021-01-16T02:31:05.2523698Z         other = [index[0], breaks[0], "foo"]
2021-01-16T02:31:05.2524100Z         result = op(index, other)
2021-01-16T02:31:05.2524497Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2524958Z >       assert_func(result, expected)
2021-01-16T02:31:05.2525215Z 
2021-01-16T02:31:05.2525528Z pandas/tests/arithmetic/test_interval.py:287: 
2021-01-16T02:31:05.2526028Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2021-01-16T02:31:05.2526680Z pandas/_libs/testing.pyx:46: in pandas._libs.testing.assert_almost_equal
2021-01-16T02:31:05.2527142Z     cpdef assert_almost_equal(a, b,
2021-01-16T02:31:05.2527546Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2021-01-16T02:31:05.2527956Z 
2021-01-16T02:31:05.2528320Z >   raise_assert_detail(obj, msg, lobj, robj, index_values=index_values)
2021-01-16T02:31:05.2528734Z E   AssertionError: Series are different
2021-01-16T02:31:05.2529231Z E   
2021-01-16T02:31:05.2529534Z E   Series values are different (33.33333 %)
2021-01-16T02:31:05.2529923Z E   [index]: [0, 1, 2]
2021-01-16T02:31:05.2530368Z E   [left]:  [False, False, False]
2021-01-16T02:31:05.2530715Z E   [right]: [True, False, False]
2021-01-16T02:31:05.2531028Z 
2021-01-16T02:31:05.2531331Z pandas/_libs/testing.pyx:161: AssertionError
2021-01-16T02:31:05.2532134Z _ TestComparison.test_index_series_compat[ne-IntervalIndex-array-assert_numpy_array_equal] _
2021-01-16T02:31:05.2532992Z [gw1] linux -- Python 3.8.5 /home/vsts/miniconda3/envs/pandas-dev/bin/python
2021-01-16T02:31:05.2533317Z 
2021-01-16T02:31:05.2533705Z self = <pandas.tests.arithmetic.test_interval.TestComparison object at 0x7f7984d5c5e0>
2021-01-16T02:31:05.2534243Z op = <built-in function ne>
2021-01-16T02:31:05.2534860Z constructor = <class 'pandas.core.indexes.interval.IntervalIndex'>
2021-01-16T02:31:05.2535420Z expected_type = <built-in function array>
2021-01-16T02:31:05.2535864Z assert_func = <function assert_numpy_array_equal at 0x7f79d19fb280>
2021-01-16T02:31:05.2536160Z 
2021-01-16T02:31:05.2536407Z     @pytest.mark.parametrize(
2021-01-16T02:31:05.2536807Z         "constructor, expected_type, assert_func",
2021-01-16T02:31:05.2537102Z         [
2021-01-16T02:31:05.2537468Z             (IntervalIndex, np.array, tm.assert_numpy_array_equal),
2021-01-16T02:31:05.2537854Z             (Series, Series, tm.assert_series_equal),
2021-01-16T02:31:05.2538200Z         ],
2021-01-16T02:31:05.2538511Z     )
2021-01-16T02:31:05.2538887Z     def test_index_series_compat(self, op, constructor, expected_type, assert_func):
2021-01-16T02:31:05.2606624Z         # IntervalIndex/Series that rely on IntervalArray for comparisons
2021-01-16T02:31:05.2607151Z         breaks = range(4)
2021-01-16T02:31:05.2687364Z         index = constructor(IntervalIndex.from_breaks(breaks))
2021-01-16T02:31:05.2687833Z     
2021-01-16T02:31:05.2688104Z         # scalar comparisons
2021-01-16T02:31:05.2688414Z         other = index[0]
2021-01-16T02:31:05.2688719Z         result = op(index, other)
2021-01-16T02:31:05.2689117Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2689504Z         assert_func(result, expected)
2021-01-16T02:31:05.2689783Z     
2021-01-16T02:31:05.2690033Z         other = breaks[0]
2021-01-16T02:31:05.2690325Z         result = op(index, other)
2021-01-16T02:31:05.2690722Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2691115Z         assert_func(result, expected)
2021-01-16T02:31:05.2691394Z     
2021-01-16T02:31:05.2692145Z         # list-like comparisons
2021-01-16T02:31:05.2692512Z         other = IntervalArray.from_breaks(breaks)
2021-01-16T02:31:05.2692846Z         result = op(index, other)
2021-01-16T02:31:05.2693221Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2693623Z         assert_func(result, expected)
2021-01-16T02:31:05.2693887Z     
2021-01-16T02:31:05.2694180Z         other = [index[0], breaks[0], "foo"]
2021-01-16T02:31:05.2694546Z         result = op(index, other)
2021-01-16T02:31:05.2694934Z         expected = expected_type(self.elementwise_comparison(op, index, other))
2021-01-16T02:31:05.2695322Z >       assert_func(result, expected)
2021-01-16T02:31:05.2695556Z 
2021-01-16T02:31:05.2695863Z pandas/tests/arithmetic/test_interval.py:287: 
2021-01-16T02:31:05.2696276Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
2021-01-16T02:31:05.2696602Z 
2021-01-16T02:31:05.2696918Z left = array([ True,  True,  True]), right = array([False,  True,  True])
2021-01-16T02:31:05.2697265Z err_msg = None
2021-01-16T02:31:05.2697480Z 
2021-01-16T02:31:05.2697762Z     def _raise(left, right, err_msg):
2021-01-16T02:31:05.2698114Z         if err_msg is None:
2021-01-16T02:31:05.2698459Z             if left.shape != right.shape:
2021-01-16T02:31:05.2698803Z                 raise_assert_detail(
2021-01-16T02:31:05.2699198Z                     obj, f"{obj} shapes are different", left.shape, right.shape
2021-01-16T02:31:05.2699761Z                 )
2021-01-16T02:31:05.2700009Z     
2021-01-16T02:31:05.2700245Z             diff = 0
2021-01-16T02:31:05.2700598Z             for left_arr, right_arr in zip(left, right):
2021-01-16T02:31:05.2700997Z                 # count up differences
2021-01-16T02:31:05.2701434Z                 if not array_equivalent(left_arr, right_arr, strict_nan=strict_nan):
2021-01-16T02:31:05.2701881Z                     diff += 1
2021-01-16T02:31:05.2702133Z     
2021-01-16T02:31:05.2702418Z             diff = diff * 100.0 / left.size
2021-01-16T02:31:05.2702802Z             msg = f"{obj} values are different ({np.round(diff, 5)} %)"
2021-01-16T02:31:05.2703257Z >           raise_assert_detail(obj, msg, left, right, index_values=index_values)
2021-01-16T02:31:05.2703684Z E           AssertionError: numpy array are different
2021-01-16T02:31:05.2704002Z E           
2021-01-16T02:31:05.2704325Z E           numpy array values are different (33.33333 %)
2021-01-16T02:31:05.2704694Z E           [left]:  [True, True, True]
2021-01-16T02:31:05.2705054Z E           [right]: [False, True, True]
2021-01-16T02:31:05.2705306Z 
2021-01-16T02:31:05.2705579Z pandas/_testing.py:1159: AssertionError
2021-01-16T02:31:05.2706269Z _ TestComparison.test_index_series_compat[ne-Series-Series-assert_series_equal] _
2021-01-16T02:31:05.2706975Z [gw1] linux -- Python 3.8.5 /home/vsts/miniconda3/envs/pandas-dev/bin/python
```

