### Sagecell kwargs no longer works

A week or so ago, I spent quite a lot of time with some sagecell code, but it no longer seems to work.

In particular, if I ran the following code on aleph:

@interact
def f(denominator=2):
print "denominator must be an even integer"
assert type(denominator) == Integer
assert denominator % 2 == 0
@interact(controls=[('t', (-1/2,1,1/denominator))])
def s(multiplier=2, **kwargs):
assert multiplier > 0
print kwargs.keys()

I would now get an empty list, whereas a week or 10 days ago, I got 't'. As a result, my code is now irretrievably broken.

What changed and how can I either fix it or restore the old version?