diff --git a/examples/advection/var-velocity.py b/examples/advection/var-velocity.py
index de1b45354..a917c38f4 100644
--- a/examples/advection/var-velocity.py
+++ b/examples/advection/var-velocity.py
@@ -215,12 +215,13 @@ def rhs(t, u):
             norm_u = actx.to_numpy(op.norm(dcoll, event.state_component, 2))
             plot(event, "fld-var-velocity-%04d" % step)
 
+            logger.info("[%04d] t = %.5f |u| = %.5e", step, event.t, norm_u)
+            # NOTE: These are here to ensure the solution is bounded for the
+            # time interval specified
+            assert norm_u < 1
+
         step += 1
-        logger.info("[%04d] t = %.5f |u| = %.5e", step, event.t, norm_u)
 
-        # NOTE: These are here to ensure the solution is bounded for the
-        # time interval specified
-        assert norm_u < 1
 
     # }}}
 
diff --git a/grudge/models/em.py b/grudge/models/em.py
index 938e98e87..05859a3d6 100644
--- a/grudge/models/em.py
+++ b/grudge/models/em.py
@@ -246,6 +246,8 @@ def flux(self, wtpair):
             e, h = self.split_eh(wtpair)
             epsilon = self.epsilon
             mu = self.mu
+        else:
+            raise NotImplementedError("only fixed material spported for now")
 
         Z_int = (mu/epsilon)**0.5  # noqa: N806
         Y_int = 1/Z_int  # noqa: N806
@@ -348,6 +350,8 @@ def absorbing_bc(self, w):
         if self.fixed_material:
             epsilon = self.epsilon
             mu = self.mu
+        else:
+            raise NotImplementedError("only fixed material supported for now")
 
         absorb_Z = (mu/epsilon)**0.5  # noqa: N806
         absorb_Y = 1/absorb_Z  # noqa: N806
@@ -394,6 +398,8 @@ def operator(self, t, w):
             # need to check this
             material_divisor = (
                     [self.epsilon]*elec_components+[self.mu]*mag_components)
+        else:
+            raise NotImplementedError("only fixed material supported for now")
 
         tags_and_bcs = [
                 (self.pec_tag, self.pec_bc(w)),
@@ -567,9 +573,6 @@ def get_rectangular_cavity_mode(actx, nodes, t, E_0, mode_indices):  # noqa: N80
     cx = actx.np.cos(kx*x)
     sy = actx.np.sin(ky*y)
     cy = actx.np.cos(ky*y)
-    if dims == 3:
-        sz = actx.np.sin(kz*z)
-        cz = actx.np.cos(kz*z)
 
     if dims == 2:
         tfac = t * omega
@@ -584,7 +587,10 @@ def get_rectangular_cavity_mode(actx, nodes, t, E_0, mode_indices):  # noqa: N80
              * np.sin(tfac) / omega),  # hy
             zeros,
         )
-    else:
+    elif dims == 3:
+        sz = actx.np.sin(kz*z)
+        cz = actx.np.cos(kz*z)
+
         tdep = np.exp(-1j * omega * t)
 
         gamma_squared = ky**2 + kx**2
@@ -596,6 +602,8 @@ def get_rectangular_cavity_mode(actx, nodes, t, E_0, mode_indices):  # noqa: N80
             1j * omega * kx*E_0*cx*sy*cz*tdep / gamma_squared,
             zeros,
         )
+    else:
+        raise NotImplementedError("only 2D and 3D supported")
 
     return result
 
diff --git a/test/test_grudge.py b/test/test_grudge.py
index 022545ca5..3686e1d10 100644
--- a/test/test_grudge.py
+++ b/test/test_grudge.py
@@ -349,7 +349,7 @@ def test_face_normal_surface(actx_factory, mesh_name):
                 dof_desc.FACE_RESTR_INTERIOR, dof_desc.VTAG_ALL)
             )(face_normal_i)
 
-    if mesh.ambient_dim == 3:
+    if ambient_dim == 3:
         from grudge.geometry import pseudoscalar, area_element
         # NOTE: there's only one face tangent in 3d
         face_tangent = (