ASDF 3.1.7.43 is 3.2 release candidate

[Anton Vodonosov]

PS: SBCL 1.1.16 and later don't have this error. 

In 1.1.11 sb-posix.asd contains full system definition,
while in 1.1.16 sb-posix.asd contains just one line: (defsystem :sb-posix :class require-system),
so I think ASDF just doesn't try to signal the warning.