I deployed an update to calm today which should add evicting stale package versions (package versions that are no longer accessible by the installer) from the release area.
By default, the package versions retained are those used by the curr:, keep: and test: versions (either by being explicitly assigned to those labels, or implicitly chosen for them)
When an upload causes older package versions to be evicted, these should be listed in the upload report.
Tuning to retain additional package versions can be controlled via keys in an override.hint file (see [1] for details), but setup is not capable of being told about these additional versions, so they can't be installed currently (see the thread preceding [2] for discussion of that)
[1] https://sourceware.org/git/gitweb.cgi?p=cygwin-apps/calm.git;a=commit;h=2a73f7ead10a2e4756c3ed199c8dc65109cdd435
[2] https://cygwin.com/ml/cygwin-apps/2016-08/msg00114.html
