IndexError: tuple index out of range error from pm.sample

Can you try this?

import pymc as pm


if __name__ == "__main__":

    with pm.Model() as model:
        p = pm.Beta("p", alpha=1, beta=1)
        y = pm.Binomial("y", n=10, p=p, observed=[1,1,0,0])
        idata = pm.sample()