Error: SymbolRef of Dimension not found in offset provider

[jeffzwe]

Run configuration: Daint, gt4py version: 1.0.1

Description:

SymbolRef no found error for the offset_provider-entry 'Koff': K, where  K is a Dimension. 
The error does not occur when the field_operator contains the Dimension K in some way. 
For example if the return-type is Field[[Vertex, K], float_type] then the error does not occur.

Code:

@field_operator(backend=build_config.backend, grid_type=GridType.UNSTRUCTURED)
def initial_rho_test(
    mesh_xydeg_x: Field[[Vertex], float_type],
) -> Field[[Vertex], float_type]:
    return mesh_xydeg_x

out_test = as_field([Vertex], np.zeros(400))

initial_rho_test(
    mesh.xydeg_x,
    out=out_test,
    offset_provider=mesh.offset_provider,
)

Error:

Traceback (most recent call last):
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/otf/workflow.py", line 253, in __call__
    result = self._cache[hash_]
KeyError: 2189759977640088703

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/users/zjeffrey/gt-gpu/GridTools/../fvm_advection_sphere/tests/advection.py", line 115, in <module>
    initial_rho_test(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/ffront/decorator.py", line 716, in __call__
    return self.as_program(arg_types, kwarg_types)(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/ffront/decorator.py", line 306, in __call__
    self.backend(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/program_processors/otf_compile_executor.py", line 54, in __call__
    self.otf_workflow(stages.ProgramCall(program, args, kwargs))(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/otf/workflow.py", line 255, in __call__
    result = self._cache[hash_] = self.step(inp)
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/otf/workflow.py", line 144, in __call__
    step_result = getattr(self, step_name)(step_result)
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/program_processors/codegens/gtfn/gtfn_module.py", line 216, in __call__
    stencil_src = gtfn_backend.generate(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/program_processors/codegens/gtfn/gtfn_backend.py", line 70, in generate
    gtfn_ir = _lower(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/program_processors/codegens/gtfn/gtfn_backend.py", line 39, in _lower
    gtfn_ir = GTFN_lowering.apply(
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/program_processors/codegens/gtfn/itir_to_gtfn_ir.py", line 242, in apply
    ).visit(node)
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/eve/traits.py", line 169, in visit
    result = super().visit(node, **kwargs)
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/eve/visitors.py", line 122, in visit
    return visitor(node, **kwargs)
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/next/program_processors/codegens/gtfn/itir_to_gtfn_ir.py", line 549, in visit_FencilDefinition
    return FencilDefinition(
  File "<attrs generated init gt4py.next.program_processors.codegens.gtfn.gtfn_ir.FencilDefinition>", line 18, in __init__
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/eve/datamodels/core.py", line 943, in __attrs_post_init__
    validator.__get__(self)(self)
  File "/users/zjeffrey/gt-gpu/gt4py/src/gt4py/eve/traits.py", line 112, in _validate_symbol_refs
    raise exceptions.EveValueError(
gt4py.eve.exceptions.EveValueError: Symbols {SymbolRef('K')} not found.

Offset_provider:

{'V2V': <gt4py.next.iterator.embedded.NeighborTableOffsetProvider object at 0x15344e4ab310>, 
'V2E': <gt4py.next.iterator.embedded.NeighborTableOffsetProvider object at 0x1534893528c0>, 
'E2V': <gt4py.next.iterator.embedded.NeighborTableOffsetProvider object at 0x15344e4a92d0>, 
'Koff': Dimension(value='K', kind=<DimensionKind.VERTICAL: 'vertical'>)}