latest Emacs 28 (..) won't compile slime at the moment

[Gijs Hillenius <gijs@hillenius.net>]

Dear CL team,

first: happy new year!

I thought I should let you know that this year (2021) a snapshot of
emacs (using the unofficial Debian emacs-snapshot) will complain about
the Debian slime package, with two errors:

,----[ first error ]
| In toplevel form:
| slime-tests.el:28:1: Warning: Package cl is deprecated
`----

slime-tests line 28 is (require 'slime), and in the latter I see line 66
has a (require 'cl): "(eval-when-compile (require 'cl)) ; defsetf,
lexical-let". Perhaps *that* causes the error?

,----[ second error ]
| In toplevel form:
| slime.el:72:1: Error: Wrong number of arguments: (3 . 4), 2
`----
line 72 is: (require 'hyperspec "lib/hyperspec")

I don't yet have a clue why that would result in an error.

Kind greetings

Gijs