$ cabal new-build all
Build profile: -w ghc-8.6.1.20180716 -O1
In order, the following will be built (use -v for more details):
 - example-0.1.0.0 (exe:example) (dependency rebuilt)
Preprocessing executable 'example' for example-0.1.0.0..
Building executable 'example' for example-0.1.0.0..
[1 of 1] Compiling Main             ( Main.hs, /home/ollie/work/hlint-source-plugin/dist-newstyle/build/x86_64-linux/ghc-8.6.1.20180716/example-0.1.0.0/x/example/build/example/example-tmp/Main.o ) [Plugin forced recompilation]
Main.hs:4:8: warning:
    • Redundant do
    • Why not: (putStrLn $ (show "Hello"))
  |
4 | main = do
  |        ^^...
Main.hs:4:8: warning:
    • Redundant bracket
    • Why not: do putStrLn $ (show "Hello")
  |
4 | main = do
  |        ^^...
Main.hs:5:4: warning:
    • Use print
    • Why not: print "Hello"
  |
5 |   (putStrLn $ (show "Hello"))
  |    ^^^^^^^^^^^^^^^^^^^^^^^^^
Main.hs:5:4: warning:
    • Redundant bracket
    • Why not: putStrLn $ show "Hello"
  |
5 |   (putStrLn $ (show "Hello"))
  |    ^^^^^^^^^^^^^^^^^^^^^^^^^
Main.hs:5:4: warning:
    • Redundant $
    • Why not: putStrLn (show "Hello")
  |
5 |   (putStrLn $ (show "Hello"))
  |    ^^^^^^^^^^^^^^^^^^^^^^^^^