Main.hs

module Main where

import           Control.Exception
import           GHC.Stack

main :: IO ()
main = do
  catch letMeCall handler
  _ <- getLine
  return ()
  where
    handler :: SomeException -> IO ()
    handler e = do
      stack <- currentCallStack
      who <- whoCreated e
      putStr $ unlines $ [
        "Exception encountered was: " ++ show e
        , "Who created:" ]
        ++ who
        ++ ["", "Current call stack:"]
        ++ stack

{-# NOINLINE letMeCall #-}
letMeCall = do
  putStrLn "So far so good"
  crashHere

{-# NOINLINE crashHere #-}
crashHere :: IO ()
crashHere = error "Oopsie!"

output

➜  playground stack exec .stack-work/dist/x86_64-linux-tinfo6/Cabal-2.2.0.1/build/playground-exe/playground-exe
So far so good
Exception encountered was: Oopsie!
CallStack (from HasCallStack):
  error, called at app/Main.hs:30:13 in main:Main
CallStack (from -prof):
  Main.crashHere (app/Main.hs:30:1-27)
  Main.CAF:crashHere (app/Main.hs:30:1-9)
Who created:
Main.CAF:crashHere (app/Main.hs:30:1-9)
Main.crashHere (app/Main.hs:30:1-27)

Current call stack:
Main.CAF:crashHere (app/Main.hs:30:1-9)
Main.crashHere (app/Main.hs:30:1-27)
Main.main.handler (app/Main.hs:(13,5)-(21,16))
… well ok then, bye!