ListTensor assumption fails

[Marie Elisabeth Rognes]

The below code fails with

ufl.log.UFLException: ListTensor assumption 1 failed, please report this incident as a potential bug.

from ufl import *
V = VectorElement("CG", triangle, 1)
Q = FiniteElement("CG", triangle, 1)
v = Coefficient(V)
q = Coefficient(Q)
M = MixedElement([V, Q])
as_tensor((v, q))

[Martin Sandve Alnæs]

That's not supposed to work, the only bug is a lack of error checking at an earlier point.

Try as_vector(list(v) + [q]).

[Marie Elisabeth Rognes]

Then perhaps the exception message could be modified?

[Martin Sandve Alnæs]

I think it should be caught before that point. I'll take a look but not right away.

[Martin Sandve Alnæs]

Removing milestone: 1.4 (automated comment)