[BUG]: Symmetric spaces broken

[jorgensd]

How to reproduce the bug

Based on: https://fenicsproject.discourse.group/t/projection-of-function-to-mixed-variational-form-error-dolfinx/11878?u=dokken
but simplfied.
Removing symmetry=True resolves the error.

Minimal Example (Python)

from mpi4py import MPI
import ufl
import dolfinx
mesh = dolfinx.mesh.create_unit_square(MPI.COMM_WORLD, 10, 10)
P2 = ufl.TensorElement("CG",mesh.ufl_cell(),1, symmetry=True) # strain
P1 = ufl.VectorElement("CG",mesh.ufl_cell(),1)                 # displacement

MX = ufl.MixedElement([P1,P2])
W = dolfinx.fem.FunctionSpace(mesh,MX)
W_eps, _ = W.sub(1).collapse()
u = dolfinx.fem.Function(W_eps)
p = dolfinx.fem.Function(W)
uk, _ = ufl.split(p)
v = ufl.TestFunction(W_eps)
L = ufl.inner(ufl.grad(uk), v) * ufl.dx
dolfinx.fem.form(L)

Output (Python)

python3: can't open file '/root/shared/mwe123': [Errno 2] No such file or directory
root@20eb7ebf7e20:~/shared# python3 mwe123.py 
Traceback (most recent call last):
  File "/root/shared/mwe123.py", line 9, in <module>
    W = dolfinx.fem.FunctionSpace(mesh,MX)
  File "/usr/local/dolfinx-real/lib/python3.10/dist-packages/dolfinx/fem/function.py", line 519, in __init__
    (self._ufcx_element, self._ufcx_dofmap), module, code = jit.ffcx_jit(
  File "/usr/local/dolfinx-real/lib/python3.10/dist-packages/dolfinx/jit.py", line 55, in mpi_jit
    return local_jit(*args, **kwargs)
  File "/usr/local/dolfinx-real/lib/python3.10/dist-packages/dolfinx/jit.py", line 205, in ffcx_jit
    r = ffcx.codegeneration.jit.compile_elements([ufl_object], options=p_ffcx, **p_jit)
  File "/usr/local/lib/python3.10/dist-packages/ffcx/codegeneration/jit.py", line 117, in compile_elements
    ffcx.naming.compute_signature(elements, _compute_option_signature(p)
  File "/usr/local/lib/python3.10/dist-packages/ffcx/naming.py", line 35, in compute_signature
    object_signature += repr(convert_element(ufl_object))
  File "/usr/local/lib/python3.10/dist-packages/ffcx/element_interface.py", line 27, in convert_element
    return _cached_conversion(element)
  File "/usr/local/lib/python3.10/dist-packages/ffcx/element_interface.py", line 57, in _cached_conversion
    return basix.ufl.mixed_element([_cached_conversion(e) for e in element.sub_elements()])
  File "/usr/local/lib/python3.10/dist-packages/ffcx/element_interface.py", line 57, in <listcomp>
    return basix.ufl.mixed_element([_cached_conversion(e) for e in element.sub_elements()])
  File "/usr/local/lib/python3.10/dist-packages/ffcx/element_interface.py", line 54, in _cached_conversion
    return basix.ufl.blocked_element(_cached_conversion(element.sub_elements()[0]),
  File "/usr/local/lib/python3.10/dist-packages/basix/ufl.py", line 1492, in blocked_element
    shape = tuple(tdim for _ in range(rank))
TypeError: 'tuple' object cannot be interpreted as an integer

Version

main branch

DOLFINx git commit

200e94c

Installation

Using docker, docker run -ti -v $(pwd):/root/shared -w /root/shared --rm ghcr.io/fenics/dolfinx/dolfinx:nightly

Additional information

No response

[conpierce8]

A similar MWE (see FEniCS/basix#717 (comment)) seems to be working now*, pending a small change to basix.ufl._BlockedElement.

*Where "now" is defined as:

python3 -c "import dolfinx;print(dolfinx.__version__);print(dolfinx.git_commit_hash)"
0.8.0.0
53d821d028b6951d1dac472a6849516a2d9ca4e8

[francesco-ballarin]

@conpierce8 @mscroggs has FEniCS/basix#718 fixed this?