I was bitten by #8707 and I had no idea what was going on, had to search the issue tracker to find it.
Looks like now cabal haddock will with default settings (i.e. no documentation: True in the config file or --disable-documentation passed explicitly) lead to rebuild of all dependencies.
What is worse, if someone doesn't want to enable documentation: True, there seems to be no way to permanently disable this behavior.
This looks like a quite bad UX change to me.
Can this please be reverted? Or resolved in a better way.
PRs in question: