ghc stacktraces

main.hs

{-# LANGUAGE RankNTypes #-}

import Control.Monad (forM_)
import GHC.Stack

httpCall :: HasCallStack => IO ()
httpCall = do
  putStrLn $ prettyCallStack $ callStack
  print "http resolved"

retry :: HasCallStack => (HasCallStack => IO()) -> IO ()
retry op = do
  forM_ [1] $ \i -> do
    op

main = retry httpCall

output.txt

GHCi, version 8.6.5
   
CallStack (from HasCallStack):
  httpCall, called at main.hs:16:14 in main:Main
  op, called at main.hs:14:5 in main:Main
  retry, called at main.hs:16:8 in main:Main
"http resolved"