Fails to build

I am new to Haskell, just tried building following some generic Haskell tutorial, but it fails with

```
coformat/src/Clang/Format/Formatter.hs:42:22: error:
    Data constructor not in scope: C :: Language
   |
42 |         languages = [C, Cpp]
   |                      ^


--  While building package coformat-0.3.0.0 (scroll up to its section to see the error) using:
```