I found the documentation on the c-string type to be hard to
understand, but I think this is legal:
(sb-alien:with-alien ((x sb-alien:c-string "foo"))
It works, but also gives the error
; caught WARNING:
; This is not a STRING:
; See also:
; The SBCL Manual, Node "Handling of Types"
(Of course this example isn't useful, but you get the same error if
you use an alien string as the initializer.)
This is in SBCL 1.0.3 that I compiled for Linux x86.