cabal install --help says this about --shadow-installed-packages:
If multiple package instances of the same version are installed, treat all but one as shadowed.
But I used this option in a sandbox and it seems that all installed packages were shadowed, and everything was rebuilt in the sandbox. This was actually what I expected based on the name of the option, but it doesn’t seem to match the help description.
What is this option really supposed to do?
