GHC 9.4 compatibility

[arybczak]

cleff just needs bumps of upper versions of base and template-haskell to build with 9.4.1.

Unfortunately the story for cleff-plugin seems to be more complicated due to removal of derived constraints.

[ErnestKz]

It wasn't too complicated, just a few shifts in the data constructors.
#29

[ErnestKz]

Though I take it back, some extra work is needed to for the CPP pragmas.

[goertzenator]

Any luck on the plugin?

[ErnestKz]

Hi. To let you know. I'm personally not aiming at fixing this issue at the moment.

Though an example of a fix can be seen here:
polysemy-research/polysemy@f9b19c0

[tomjaguarpaw]

cleff seems to build fine on 9.4 and 9.6. Is this issue resolved?

(Relatedly, it requires --allow-newer for 9.8)

[goertzenator]

Just a heads up that ghc-9.6 has problems with plugins in general. The link below is for polysemy, but I've had the same trouble in effectful. Surely cleff is affected too.

Ref commercialhaskell/stack#6251