import firedrake as fd

mesh = fd.UnitIntervalMesh(1)
space = fd.FunctionSpace(mesh, "DG", 0)
u = fd.Cofunction(space.dual(), name="u")
u.interpolate(u)

Traceback (most recent call last):
  File "/home/jmaddis2/test.py", line 6, in <module>
    u.interpolate(u)
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/cofunction.py", line 317, in interpolate
    return firedrake.assemble(interp, tensor=self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "petsc4py/PETSc/Log.pyx", line 188, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "petsc4py/PETSc/Log.pyx", line 189, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/adjoint_utils/assembly.py", line 30, in wrapper
    output = assemble(form, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/assemble.py", line 134, in assemble
    return get_assembler(expr, *args, **kwargs).assemble(tensor=tensor)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/assemble.py", line 382, in assemble
    result = BaseFormAssembler.base_form_postorder_traversal(self._form, visitor, visited)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/assemble.py", line 605, in base_form_postorder_traversal
    visited[e] = visitor(e, *(visited[arg] for arg in operands))
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/assemble.py", line 378, in visitor
    return self.base_form_assembly_visitor(e, t, *operands)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/assemble.py", line 545, in base_form_assembly_visitor
    return interpolator._interpolate(v, output=output, transpose=True, default_missing_val=default_missing_val)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "petsc4py/PETSc/Log.pyx", line 188, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "petsc4py/PETSc/Log.pyx", line 189, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func
  File "/home/jmaddis2/build/firedrake/firedrake/src/firedrake/firedrake/interpolation.py", line 862, in _interpolate
    mul(x, out)
  File "petsc4py/PETSc/Mat.pyx", line 3760, in petsc4py.PETSc.Mat.multTranspose
petsc4py.PETSc.Error: error code 73
[0] MatMultTranspose() at /home/jmaddis2/build/firedrake/firedrake/src/petsc/src/mat/interface/matrix.c:2710
[0] Object is in wrong state
[0] x and y must be different vectors