I just grabbed the latest ITERATE source off of its gitlab repository, and, yeah, that bit is still giving an error:

      Iterate, in (COUNT I SOME-SEQUENCE): Missing value for SOME-SEQUENCE keyword

as well as

    WARNING:
       COUNT appears to be used as an ITERATE clause keyword, in this sexpression: (COUNT I SOME-SEQUENCE).
       This use is now deprecated and will cease to be supported in a future version. Please use the alternative keyword COUNTING instead. If you intended COUNT to be interpreted as a function call, instead of an ITERATE clause, you must find an alternative way of calling it, at present, perhaps by using FUNCALL or APPLY.

Have to use

    (iter (for i from 1 to 10)
        (print (funcall #'count i some-sequence)))

Guess the documentation /is/ wrong (for now, until the code finishes catching up)