Documentation for the arguments of the effect-performing function is not being generated

[ymdfield]

There appears to be a bug in the automatic generation of documentation for the arguments of effect operation functions. Documentation is not being generated for any arguments except the last one.

https://hackage.haskell.org/package/data-effects-0.3.0.1/docs/Data-Effect-Concurrent-Parallel.html#v:liftP2

data-effects/data-effects-th/src/Data/Effect/TH/Internal.hs

Lines 395 to 398 in c8cae9c

	forM [0 .. length effParamTypes - 1] \i -> do
	argDoc <- getDoc $ ArgDoc effName i
	_senderFnArgDoc i argDoc >>= mapM_ \doc -> do
	addModFinalizer $ putDoc (ArgDoc fnName i) doc

[ymdfield]

1. I tried moving addModFinalizer outside the loop, but it doesn't seem to be related.
2. Applying reverse to [0..length effParamTypes - 1] made no difference.
3. When I set it to length effParamTypes - 2, only the argument before the last one is output.

If I’m not mistaken, I think this is an issue with Template Haskell’s putDoc function, which might not support outputting multiple arguments in ArgDoc. When attempting to have putDoc output multiple arguments, it seems to only output the last one in the set of requested arguments. Should I report this to GHC?

[ymdfield]

I inserted Debug.Trace, and it appears that everything works correctly up to the point of retrieving with getDoc (the documentation for all arguments was displayed in the log).