Confusing package state for packages whose download artefact has been deleted but whose package is still installed.

[alecthomas]

In this situation the package will be shown as "installed", but executing anything from it will result in the artefact downloading anyway:

~/Development/hermit $ ls -l /Users/aat/Library/Java/JavaVirtualMachines/jdk-11.0.8_10.jdk/Contents
total 8
dr-x------  10 aat  staff   320 Dec 30 22:16 Home/
r-------   1 aat  staff  1577 Jul 15  2020 Info.plist
dr-x------   3 aat  staff    96 Dec 30 22:16 MacOS/
~/Development/hermit $ ./bin/java                                                                                                                                                                                                                                                                                                                                                                                                                                                          /Users/aat/Library/Java/JavaVirtualMachines/jdk-11.0.8_10.jdk/Contents/Homeopenjdk-11.0....   
16s [=================================>---------] download  78%

I guess in this situation we probably don't need to download, or we should remove the installed package and then download.