Nested reflected list fails to type with inner lists of differing types.

The code below works:

import numpy as np
import numba as nb

@nb.njit()
def func():
    inp_arr = np.array([2, 3j], dtype =nb.complex128)
    return

func()

but if you make it a multidimensional array, such as in the code below, the code breaks:

import numpy as np
import numba as nb

@nb.njit()
def func():
    inp_arr = np.array([[1, 0],
                        [2, 3j]], dtype =nb.complex128)
    return

func()

This gives me the error:

Traceback (most recent call last):

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\spyder_kernels\py3compat.py", line 356, in compat_exec
    exec(code, globals, locals)

  File "c:\users\micha\onedrive\documenten\uni shit\thesis\pythonforthesis\untitled0.py", line 10, in <module>
    func()

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\dispatcher.py", line 487, in _compile_for_args
    raise e

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\dispatcher.py", line 420, in _compile_for_args
    return_val = self.compile(tuple(argtypes))

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\dispatcher.py", line 965, in compile
    cres = self._compiler.compile(args, return_type)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\dispatcher.py", line 125, in compile
    status, retval = self._compile_cached(args, return_type)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\dispatcher.py", line 139, in _compile_cached
    retval = self._compile_core(args, return_type)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\dispatcher.py", line 152, in _compile_core
    cres = compiler.compile_extra(self.targetdescr.typing_context,

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler.py", line 693, in compile_extra
    return pipeline.compile_extra(func)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler.py", line 429, in compile_extra
    return self._compile_bytecode()

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler.py", line 497, in _compile_bytecode
    return self._compile_core()

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler.py", line 476, in _compile_core
    raise e

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler.py", line 463, in _compile_core
    pm.run(self.state)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler_machinery.py", line 353, in run
    raise patched_exception

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler_machinery.py", line 341, in run
    self._runPass(idx, pass_inst, state)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler_lock.py", line 35, in _acquire_compile_lock
    return func(*args, **kwargs)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler_machinery.py", line 296, in _runPass
    mutated |= check(pss.run_pass, internal_state)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\compiler_machinery.py", line 269, in check
    mangled = func(compiler_state)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\typed_passes.py", line 394, in run_pass
    lower.lower()

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 196, in lower
    self.lower_normal_function(self.fndesc)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 250, in lower_normal_function
    entry_block_tail = self.lower_function_body()

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 279, in lower_function_body
    self.lower_block(block)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 293, in lower_block
    self.lower_inst(inst)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 438, in lower_inst
    val = self.lower_assign(ty, inst)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 624, in lower_assign
    return self.lower_expr(ty, value)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 1319, in lower_expr
    castvals = [self.context.cast(self.builder, val, fromty,

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\lowering.py", line 1319, in <listcomp>
    castvals = [self.context.cast(self.builder, val, fromty,

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\core\base.py", line 713, in cast
    return impl(self, builder, fromty, toty, val)

  File "C:\Users\Micha\Downloads\Laptop-Python\ANACONDA\lib\site-packages\numba\cpython\listobj.py", line 1131, in list_to_list
    assert fromty.dtype == toty.dtype

AssertionError: Failed in nopython mode pipeline (step: native lowering)

[esc]

Comment from the dev meeting: probably a better error message is worthwhile.

[esc]

@Rafnus since this concerns the reflected list which is deprecated, I think this is a bug, but it is unlikely that anyone will fix this.

See also: https://numba.readthedocs.io/en/stable/reference/pysupported.html#list