np.vectorize fails with output dtype datetime64[ns] #25936

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[1], line 4
      2 otype = "datetime64[ns]"
      3 arr = np.array(['2024-01-01', '2024-01-02', '2024-01-03'], dtype='datetime64[ns]')
----> 4 np.vectorize(lambda x: x, signature="(i)->(j)", otypes=[otype])(arr)

File ~/envs/test-xarray/lib/python3.10/site-packages/numpy/lib/function_base.py:2372, in vectorize.__call__(self, *args, **kwargs)
   2369     self._init_stage_2(*args, **kwargs)
   2370     return self
-> 2372 return self._call_as_normal(*args, **kwargs)

File ~/envs/test-xarray/lib/python3.10/site-packages/numpy/lib/function_base.py:2365, in vectorize._call_as_normal(self, *args, **kwargs)
   2362     vargs = [args[_i] for _i in inds]
   2363     vargs.extend([kwargs[_n] for _n in names])
-> 2365 return self._vectorize_call(func=func, args=vargs)

File ~/envs/test-xarray/lib/python3.10/site-packages/numpy/lib/function_base.py:2446, in vectorize._vectorize_call(self, func, args)
   2444 """Vectorized call to `func` over positional `args`."""
   2445 if self.signature is not None:
-> 2446     res = self._vectorize_call_with_signature(func, args)
   2447 elif not args:
   2448     res = func()

File ~/envs/test-xarray/lib/python3.10/site-packages/numpy/lib/function_base.py:2506, in vectorize._vectorize_call_with_signature(self, func, args)
   2502         outputs = _create_arrays(broadcast_shape, dim_sizes,
   2503                                  output_core_dims, otypes, results)
   2505     for output, result in zip(outputs, results):
-> 2506         output[index] = result
   2508 if outputs is None:
   2509     # did not call the function even once
   2510     if otypes is None:

ValueError: Cannot convert from specific units to generic units in NumPy datetimes or timedeltas

1.26.4
3.10.1 (main, Dec 15 2021, 17:45:54) [GCC 9.3.0]

[{'numpy_version': '1.26.4',
  'python': '3.10.1 (main, Dec 15 2021, 17:45:54) [GCC 9.3.0]',
  'uname': uname_result(system='Linux', node='ip-172-34-24-37', release='5.15.0-1051-aws', version='#56~20.04.1-Ubuntu SMP Tue Nov 28 15:43:31 UTC 2023', machine='x86_64')},
 {'simd_extensions': {'baseline': ['SSE', 'SSE2', 'SSE3'],
                      'found': ['SSSE3',
                                'SSE41',
                                'POPCNT',
                                'SSE42',
                                'AVX',
                                'F16C',
                                'FMA3',
                                'AVX2',
                                'AVX512F',
                                'AVX512CD',
                                'AVX512_SKX'],
                      'not_found': ['AVX512_KNL',
                                    'AVX512_KNM',
                                    'AVX512_CLX',
                                    'AVX512_CNL',
                                    'AVX512_ICL']}},
 {'architecture': 'SkylakeX',
  'filepath': '/home/ubuntu/envs/test-xarray/lib/python3.10/site-packages/numpy.libs/libopenblas64_p-r0-0cf96a72.3.23.dev.so',
  'internal_api': 'openblas',
  'num_threads': 4,
  'prefix': 'libopenblas',
  'threading_layer': 'pthreads',
  'user_api': 'blas',
  'version': '0.3.23.dev'}]
None