Bug#766944: slime: Emacs"M-x slime"+sbcl fails with "Package SWANK-REPL does not exist." if cl-swank cache not deleted

[Milan Zamazal]

I could see the bug too and it was reproducible but after some
experiments it suddenly disappeared for reasons unknown to me and it
hasn't appeared again since then.  Apparently it has something to do
with the load ordering of contrib modules, maybe in
slime--setup-contribs in slime.el.  I might try to reproduce the bug
again but any help is appreciated.