No expected undocumented flags
The GHC repo contains this file of shame (credit to @monoidal for telling me about it): https://gitlab.haskell.org/ghc/ghc/-/blob/master/docs/users_guide/expected-undocumented-flags.txt
Some dedicated attention is all that it would take to fix this. Any volunteers?
This would also fix #18630 and #18631 along the way. #18632 mentions a language extension that is missing from that file (possibly because it starts with No
and the grepping command that produced the file probably filtered out -XNo....
extensions). #14985, #9358, and #9248 (closed) are also in this space.