cairo-sharp is_verified returns a TypeError

[nschoe]

I'm trying to experiment with the SHARP, and I've run the example of the doc page (https://www.cairo-lang.org/docs/sharp.html).

Once the job was in status PROCESSED, I tried to verify the proof with cairo-sharp is_verified --node_url https://mainnet.infura.io/v3/xxx 0xe6168c0a865aa80d724ad05627fa65fbcfe4b1d66a586e9f348f461b076072c4 but I keep getting this error:

Error: TypeError: isinstance() arg 2 must be a type or tuple of types

Parse tree:
<Node matching "32">  <-- *** We were here. ***
    <Node called "sub" matching "32">
        <RegexNode called "digits" matching "32">

Whatever string I type as the node URL I keep getting this error, which makes me think that I'm doing something wrong.
Can anyone help?