Full numba traceback for trying to call `list(x)` where x is numpy array of unicode

traceback.py

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
/usr/local/lib/python3.7/site-packages/numba/errors.py in new_error_context(fmt_, *args, **kwargs)
    661     try:
--> 662         yield
    663     except NumbaError as e:

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_block(self, block)
    257                                    loc=self.loc, errcls_=defaulterrcls):
--> 258                 self.lower_inst(inst)
    259 

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_inst(self, inst)
    300             ty = self.typeof(inst.target.name)
--> 301             val = self.lower_assign(ty, inst)
    302             self.storevar(val, inst.target.name)

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_assign(self, ty, inst)
    458         elif isinstance(value, ir.Expr):
--> 459             return self.lower_expr(ty, value)
    460 

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_expr(self, resty, expr)
   1061                         for val, fromty in zip(itemvals, itemtys)]
-> 1062             return self.context.build_list(self.builder, resty, castvals)
   1063 

/usr/local/lib/python3.7/site-packages/numba/targets/cpu.py in build_list(self, builder, list_type, items)
    123         """
--> 124         return listobj.build_list(self, builder, list_type, items)
    125 

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in build_list(context, builder, list_type, items)
    450     nitems = len(items)
--> 451     inst = ListInstance.allocate(context, builder, list_type, nitems)
    452     # Populate list

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in allocate(cls, context, builder, list_type, nitems)
    318         """
--> 319         ok, self = cls.allocate_ex(context, builder, list_type, nitems)
    320         with builder.if_then(builder.not_(ok), likely=False):

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in allocate_ex(cls, context, builder, list_type, nitems)
    255             meminfo = context.nrt.meminfo_new_varsize_dtor(
--> 256                 builder, size=allocsize, dtor=self.get_dtor())
    257             with builder.if_else(cgutils.is_null(builder, meminfo),

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in get_dtor(self)
    306         # Define and set the Dtor
--> 307         dtor = self.define_dtor()
    308         dtor_fnptr = self._builder.bitcast(dtor, cgutils.voidptr_t)

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in define_dtor(self)
    295                 intp=intp) as (idx, _):
--> 296             val = payload.getitem(idx)
    297             context.nrt.decref(builder, self.dtype, val)

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in getitem(self, idx)
     63         data_item = self._builder.load(ptr)
---> 64         return self._datamodel.from_data(self._builder, data_item)
     65 

/usr/local/lib/python3.7/site-packages/numba/datamodel/models.py in from_data(self, builder, value)
     69     def from_data(self, builder, value):
---> 70         raise NotImplementedError(self)
     71 

NotImplementedError: <numba.datamodel.models.UnicodeCharSeq object at 0x11cf670f0>

During handling of the above exception, another exception occurred:

LoweringError                             Traceback (most recent call last)
<ipython-input-33-9e7dcc2e4874> in <module>
----> 1 type(foo2(np.array(list("abc"))))

/usr/local/lib/python3.7/site-packages/numba/dispatcher.py in _compile_for_args(self, *args, **kws)
    393                     e.patch_message(''.join(e.args) + help_msg)
    394             # ignore the FULL_TRACEBACKS config, this needs reporting!
--> 395             raise e
    396 
    397     def inspect_llvm(self, signature=None):

/usr/local/lib/python3.7/site-packages/numba/dispatcher.py in _compile_for_args(self, *args, **kws)
    350                 argtypes.append(self.typeof_pyval(a))
    351         try:
--> 352             return self.compile(tuple(argtypes))
    353         except errors.TypingError as e:
    354             # Intercept typing error that may be due to an argument

/usr/local/lib/python3.7/site-packages/numba/compiler_lock.py in _acquire_compile_lock(*args, **kwargs)
     30         def _acquire_compile_lock(*args, **kwargs):
     31             with self:
---> 32                 return func(*args, **kwargs)
     33         return _acquire_compile_lock
     34 

/usr/local/lib/python3.7/site-packages/numba/dispatcher.py in compile(self, sig)
    691 
    692             self._cache_misses[sig] += 1
--> 693             cres = self._compiler.compile(args, return_type)
    694             self.add_overload(cres)
    695             self._cache.save_overload(sig, cres)

/usr/local/lib/python3.7/site-packages/numba/dispatcher.py in compile(self, args, return_type)
     74 
     75     def compile(self, args, return_type):
---> 76         status, retval = self._compile_cached(args, return_type)
     77         if status:
     78             return retval

/usr/local/lib/python3.7/site-packages/numba/dispatcher.py in _compile_cached(self, args, return_type)
     88 
     89         try:
---> 90             retval = self._compile_core(args, return_type)
     91         except errors.TypingError as e:
     92             self._failed_cache[key] = e

/usr/local/lib/python3.7/site-packages/numba/dispatcher.py in _compile_core(self, args, return_type)
    106                                       args=args, return_type=return_type,
    107                                       flags=flags, locals=self.locals,
--> 108                                       pipeline_class=self.pipeline_class)
    109         # Check typing error if object mode is used
    110         if cres.typing_error is not None and not flags.enable_pyobject:

/usr/local/lib/python3.7/site-packages/numba/compiler.py in compile_extra(typingctx, targetctx, func, args, return_type, flags, locals, library, pipeline_class)
    970     pipeline = pipeline_class(typingctx, targetctx, library,
    971                               args, return_type, flags, locals)
--> 972     return pipeline.compile_extra(func)
    973 
    974 

/usr/local/lib/python3.7/site-packages/numba/compiler.py in compile_extra(self, func)
    388         self.lifted = ()
    389         self.lifted_from = None
--> 390         return self._compile_bytecode()
    391 
    392     def compile_ir(self, func_ir, lifted=(), lifted_from=None):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in _compile_bytecode(self)
    901         """
    902         assert self.func_ir is None
--> 903         return self._compile_core()
    904 
    905     def _compile_ir(self):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in _compile_core(self)
    888         self.define_pipelines(pm)
    889         pm.finalize()
--> 890         res = pm.run(self.status)
    891         if res is not None:
    892             # Early pipeline completion

/usr/local/lib/python3.7/site-packages/numba/compiler_lock.py in _acquire_compile_lock(*args, **kwargs)
     30         def _acquire_compile_lock(*args, **kwargs):
     31             with self:
---> 32                 return func(*args, **kwargs)
     33         return _acquire_compile_lock
     34 

/usr/local/lib/python3.7/site-packages/numba/compiler.py in run(self, status)
    264                     # No more fallback pipelines?
    265                     if is_final_pipeline:
--> 266                         raise patched_exception
    267                     # Go to next fallback pipeline
    268                     else:

/usr/local/lib/python3.7/site-packages/numba/compiler.py in run(self, status)
    255                 try:
    256                     event("-- %s" % stage_name)
--> 257                     stage()
    258                 except _EarlyPipelineCompletion as e:
    259                     return e.result

/usr/local/lib/python3.7/site-packages/numba/compiler.py in stage_nopython_backend(self)
    762         """
    763         lowerfn = self.backend_nopython_mode
--> 764         self._backend(lowerfn, objectmode=False)
    765 
    766     def stage_compile_interp_mode(self):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in _backend(self, lowerfn, objectmode)
    701             self.library.enable_object_caching()
    702 
--> 703         lowered = lowerfn()
    704         signature = typing.signature(self.return_type, *self.args)
    705         self.cr = compile_result(

/usr/local/lib/python3.7/site-packages/numba/compiler.py in backend_nopython_mode(self)
    688                 self.calltypes,
    689                 self.flags,
--> 690                 self.metadata)
    691 
    692     def _backend(self, lowerfn, objectmode):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in native_lowering_stage(targetctx, library, interp, typemap, restype, calltypes, flags, metadata)
   1141         lower = lowering.Lower(targetctx, library, fndesc, interp,
   1142                                metadata=metadata)
-> 1143         lower.lower()
   1144         if not flags.no_cpython_wrapper:
   1145             lower.create_cpython_wrapper(flags.release_gil)

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower(self)
    175         if self.generator_info is None:
    176             self.genlower = None
--> 177             self.lower_normal_function(self.fndesc)
    178         else:
    179             self.genlower = self.GeneratorLower(self)

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_normal_function(self, fndesc)
    216         # Init argument values
    217         self.extract_function_arguments()
--> 218         entry_block_tail = self.lower_function_body()
    219 
    220         # Close tail of entry block

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_function_body(self)
    241             bb = self.blkmap[offset]
    242             self.builder.position_at_end(bb)
--> 243             self.lower_block(block)
    244 
    245         self.post_lower()

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_block(self, block)
    256             with new_error_context('lowering "{inst}" at {loc}', inst=inst,
    257                                    loc=self.loc, errcls_=defaulterrcls):
--> 258                 self.lower_inst(inst)
    259 
    260     def create_cpython_wrapper(self, release_gil=False):

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_inst(self, inst)
    299         if isinstance(inst, ir.Assign):
    300             ty = self.typeof(inst.target.name)
--> 301             val = self.lower_assign(ty, inst)
    302             self.storevar(val, inst.target.name)
    303 

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_assign(self, ty, inst)
    457 
    458         elif isinstance(value, ir.Expr):
--> 459             return self.lower_expr(ty, value)
    460 
    461         elif isinstance(value, ir.Var):

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_expr(self, resty, expr)
    917 
    918         elif expr.op == 'call':
--> 919             res = self.lower_call(resty, expr)
    920             return res
    921 

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_call(self, resty, expr)
    709 
    710         else:
--> 711             res = self._lower_call_normal(fnty, expr, signature)
    712 
    713         # If lowering the call returned None, interpret that as returning dummy

/usr/local/lib/python3.7/site-packages/numba/lowering.py in _lower_call_normal(self, fnty, expr, signature)
    888             argvals = [the_self] + list(argvals)
    889 
--> 890         res = impl(self.builder, argvals, self.loc)
    891         return res
    892 

/usr/local/lib/python3.7/site-packages/numba/targets/base.py in __call__(self, builder, args, loc)
   1130 
   1131     def __call__(self, builder, args, loc=None):
-> 1132         res = self._imp(self._context, builder, self._sig, args, loc=loc)
   1133         self._context.add_linking_libs(getattr(self, 'libs', ()))
   1134         return res

/usr/local/lib/python3.7/site-packages/numba/targets/base.py in wrapper(*args, **kwargs)
   1155         def wrapper(*args, **kwargs):
   1156             kwargs.pop('loc')     # drop unused loc
-> 1157             return fn(*args, **kwargs)
   1158 
   1159         # Copy the following attributes from the wrapped.

/usr/local/lib/python3.7/site-packages/numba/targets/listobj.py in list_constructor(context, builder, sig, args)
    466         return res
    467 
--> 468     return context.compile_internal(builder, list_impl, sig, args)
    469 
    470 @lower_builtin(list)

/usr/local/lib/python3.7/site-packages/numba/targets/base.py in compile_internal(self, builder, impl, sig, args, locals)
    857         *args*.
    858         """
--> 859         cres = self.compile_subroutine(builder, impl, sig, locals)
    860         return self.call_internal(builder, cres.fndesc, sig, args)
    861 

/usr/local/lib/python3.7/site-packages/numba/targets/base.py in compile_subroutine(self, builder, impl, sig, locals, flags, caching)
    844             cres = self._compile_subroutine_no_cache(builder, impl, sig,
    845                                                      locals=locals,
--> 846                                                      flags=flags)
    847             self.cached_internal_func[cache_key] = cres
    848 

/usr/local/lib/python3.7/site-packages/numba/targets/base.py in _compile_subroutine_no_cache(self, builder, impl, sig, locals, flags)
    817                                             impl, sig.args,
    818                                             sig.return_type, flags,
--> 819                                             locals=locals)
    820 
    821             # Allow inlining the function inside callers.

/usr/local/lib/python3.7/site-packages/numba/compiler.py in compile_internal(typingctx, targetctx, library, func, args, return_type, flags, locals)
   1044     pipeline = Pipeline(typingctx, targetctx, library,
   1045                         args, return_type, flags, locals)
-> 1046     return pipeline.compile_extra(func)
   1047 
   1048 

/usr/local/lib/python3.7/site-packages/numba/compiler.py in compile_extra(self, func)
    388         self.lifted = ()
    389         self.lifted_from = None
--> 390         return self._compile_bytecode()
    391 
    392     def compile_ir(self, func_ir, lifted=(), lifted_from=None):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in _compile_bytecode(self)
    901         """
    902         assert self.func_ir is None
--> 903         return self._compile_core()
    904 
    905     def _compile_ir(self):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in _compile_core(self)
    888         self.define_pipelines(pm)
    889         pm.finalize()
--> 890         res = pm.run(self.status)
    891         if res is not None:
    892             # Early pipeline completion

/usr/local/lib/python3.7/site-packages/numba/compiler_lock.py in _acquire_compile_lock(*args, **kwargs)
     30         def _acquire_compile_lock(*args, **kwargs):
     31             with self:
---> 32                 return func(*args, **kwargs)
     33         return _acquire_compile_lock
     34 

/usr/local/lib/python3.7/site-packages/numba/compiler.py in run(self, status)
    264                     # No more fallback pipelines?
    265                     if is_final_pipeline:
--> 266                         raise patched_exception
    267                     # Go to next fallback pipeline
    268                     else:

/usr/local/lib/python3.7/site-packages/numba/compiler.py in run(self, status)
    255                 try:
    256                     event("-- %s" % stage_name)
--> 257                     stage()
    258                 except _EarlyPipelineCompletion as e:
    259                     return e.result

/usr/local/lib/python3.7/site-packages/numba/compiler.py in stage_nopython_backend(self)
    762         """
    763         lowerfn = self.backend_nopython_mode
--> 764         self._backend(lowerfn, objectmode=False)
    765 
    766     def stage_compile_interp_mode(self):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in _backend(self, lowerfn, objectmode)
    701             self.library.enable_object_caching()
    702 
--> 703         lowered = lowerfn()
    704         signature = typing.signature(self.return_type, *self.args)
    705         self.cr = compile_result(

/usr/local/lib/python3.7/site-packages/numba/compiler.py in backend_nopython_mode(self)
    688                 self.calltypes,
    689                 self.flags,
--> 690                 self.metadata)
    691 
    692     def _backend(self, lowerfn, objectmode):

/usr/local/lib/python3.7/site-packages/numba/compiler.py in native_lowering_stage(targetctx, library, interp, typemap, restype, calltypes, flags, metadata)
   1141         lower = lowering.Lower(targetctx, library, fndesc, interp,
   1142                                metadata=metadata)
-> 1143         lower.lower()
   1144         if not flags.no_cpython_wrapper:
   1145             lower.create_cpython_wrapper(flags.release_gil)

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower(self)
    175         if self.generator_info is None:
    176             self.genlower = None
--> 177             self.lower_normal_function(self.fndesc)
    178         else:
    179             self.genlower = self.GeneratorLower(self)

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_normal_function(self, fndesc)
    216         # Init argument values
    217         self.extract_function_arguments()
--> 218         entry_block_tail = self.lower_function_body()
    219 
    220         # Close tail of entry block

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_function_body(self)
    241             bb = self.blkmap[offset]
    242             self.builder.position_at_end(bb)
--> 243             self.lower_block(block)
    244 
    245         self.post_lower()

/usr/local/lib/python3.7/site-packages/numba/lowering.py in lower_block(self, block)
    256             with new_error_context('lowering "{inst}" at {loc}', inst=inst,
    257                                    loc=self.loc, errcls_=defaulterrcls):
--> 258                 self.lower_inst(inst)
    259 
    260     def create_cpython_wrapper(self, release_gil=False):

/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/contextlib.py in __exit__(self, type, value, traceback)
    128                 value = type()
    129             try:
--> 130                 self.gen.throw(type, value, traceback)
    131             except StopIteration as exc:
    132                 # Suppress StopIteration *unless* it's the same exception that

/usr/local/lib/python3.7/site-packages/numba/errors.py in new_error_context(fmt_, *args, **kwargs)
    668         from numba import config
    669         tb = sys.exc_info()[2] if config.FULL_TRACEBACKS else None
--> 670         six.reraise(type(newerr), newerr, tb)
    671 
    672 

/usr/local/lib/python3.7/site-packages/numba/six.py in reraise(tp, value, tb)
    657         if value.__traceback__ is not tb:
    658             raise value.with_traceback(tb)
--> 659         raise value
    660 
    661 else:

LoweringError: Failed in nopython mode pipeline (step: nopython mode backend)
Failed in nopython mode pipeline (step: nopython mode backend)
<numba.datamodel.models.UnicodeCharSeq object at 0x11cf670f0>

File "../../../../usr/local/lib/python3.7/site-packages/numba/targets/listobj.py", line 464:
    def list_impl(iterable):
        res = []
        ^

[1] During: lowering "$0.1 = build_list(items=[])" at /usr/local/lib/python3.7/site-packages/numba/targets/listobj.py (464)
[2] During: lowering "$0.3 = call $0.1(x, func=$0.1, args=[Var(x, <ipython-input-30-e93183b126c2> (3))], kws=(), vararg=None)" at <ipython-input-30-e93183b126c2> (3)
-------------------------------------------------------------------------------
This should not have happened, a problem has occurred in Numba's internals.
You are currently using Numba version 0.45.1.

Please report the error message and traceback, along with a minimal reproducer
at: https://github.com/numba/numba/issues/new

If more help is needed please feel free to speak to the Numba core developers
directly at: https://gitter.im/numba/numba

Thanks in advance for your help in improving Numba!