Which is exactly why I specified that it needs to be something that cabal honors by default.

As a sysadmin, I'd actually prefer the flag to overwriting packages --- but I find the Haskell community usually goes in other directions than what makes sense to me from the standpoint of stability vs. usability vs. flexibility. And given that the deprecation flag was added as more or less documentation, I don't really expect that a proper disable option will be added....
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