Mac 10.15 compiling using ghc

[Uwe Brauer <oub-YB6e1s5WF/He5aOfsHch1g@public.gmane.org>]

Hi

Under linux (Ubuntu 16.04)

I run successfully 

 ghc --make striplatex.hs 
where striplatex is just

,----
| import Text.Pandoc.JSON
|     
| main = toJSONFilter stripmath
|     where stripmath (Math _ _) = Str "FORMULA"
|           stripmath x = x
`----

That nicely replaces all my mathematical formula, just by the word
FORMULA

I tried the same under Mac 10.15. 

For that I installed pandoc https://github.com/jgm/pandoc/releases/tag/2.13

I install ghc using fink (that is one of the three linux like
environments (the others are macports and homebrew).

However when I run 

 ghc --make striplatex.hs 

I obtain 

Could not find module Text.Pandoc.JSON

I admit I just started using a Mac and don't know many details.

Any help would be appreciated 

Thanks

Uwe Brauer