My Debian system has an old version of the FLEXI-STREAMS library installed as a dependency of some other Debian package. As a result, on every Lisp implementation on the system, ASDF automatically loads that library from somewhere deep in the bowels of the filesystem.
Since Quicklisp uses ASDF, (ql:quickload :flexi-streams)
always loads the Debian version of FLEXI-STREAMS, and never downloads the latest version from the Quicklisp repository.
Removing the Debian version of this library will probably break whichever Debian package depends on it.
How do I get Quicklisp to ignore the local version and go ahead and install the latest version?