@ljli, thanks for your PR! By analyzing the history of the files in this pull request, we identified @cstrahan, @Profpatsch and @k0001 to be potential reviewers.

I don’t think that fixes it; normally you can’t simply replace cabal, since it’s a distribution package.

For me it works, I'm not sure why it wouldn't but I can explain what happens.
This is just a setup dependency, which means there won't be any diamond style dependency conflicts, the package doesn't care with which Cabal version it was build, after the fact.
We do this in other places but the override way doesn't work here because Cabal is not an explicit dependency.
Generally user package-db entries take precedence over distribution package-db entries and newer packages versions take precedence over older. So even if there is a Cabal in the distribution (which won't be the case after #23614) the one we pass here will be selected and if there is an older one in the user package-db (there will be after #23614), it will be selected, since it is newer. So it all works out.

What isn't quite correct here, is that Cabal is added to libraryHaskellDepends it should be setupHaskellDepends. At the moment it makes no difference, but I will change it, quickly.

By user package-db I mean the one we construct and pass explicitly, not some literal user package-db.

Ah, I see! Then I suggest @peti should merge it.