(in-package (#:foo "1.0.0"))
(in-package (#:bar "2.0.0"))
(:local-nicknames (#:a #:alexandria)
(#:vp #:versioned-packages)
(let ((f (find-package '#:f))
(f1 (find-package '(#:f "1.0.0")))
(f2 (find-package '(#:f "2.0.0"))))
(values (list f (vp:package-version f) (f:bar))
(list f1 (vp:package-version v1) (f1:bar))
(list f2 (vp:package-version v2) (f2:bar)))))
(#<PACKAGE "FOO" "1.0.0"> "1.0.0" 1)
(#<PACKAGE "FOO" "2.0.0"> "2.0.0" 2)