Dear all,
compiling "iolib-tests" I received the following error:

    #<IPv4 datagram socket, closed 00000000050f3660> is not of type STREAM.
    [Condition of type TYPE-ERROR]

I have seen that in "clos/streams.lsp" the following method is defined:   

  (defmethod close ((stream t) &key abort)
     (declare (ignore abort))
     (bug-or-error stream 'close))

Removing the method above with:
     (remove-method #'gray:close (find-method #'gray:close '() '(t)))

I was able to compile iolib-tests and run the tests.

  Did 71 checks.
     Pass: 59 (83%)
     Skip: 0 ( 0%)
     Fail: 12 (16%)