"unresolved constraints" when import and main missing
I gut a weird error because I forgot an import and the main method. (the commented lines in the code below)
GHCi told me to post a bug about this, so... :-)
Steps to reproduce:
> ghci
GHCi, version 8.0.2: http://www.haskell.org/ghc/ :? for help
Prelude> :l bug.hs
[1 of 1] Compiling Main ( bug.hs, interpreted )
ghc.exe: panic! (the 'impossible' happened)
(GHC version 8.0.2 for x86_64-unknown-mingw32):
initTc: unsolved constraints
WC {wc_insol = [W] printf_a2MG :: t_a2MF[tau:1] (CHoleCan: printf)}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
File bug.hs:
module Main where
import Test.Hspec
import Test.QuickCheck
-- import Text.Printf
testMovie :: Int -> Int -> Double -> Int -> Spec
testMovie card ticket perc s =
it (printf "should return Movie for card: %d, ticket: %d perc %s " card ticket (show perc)) $
movie card ticket perc `shouldBe` s
movie :: Int -> Int -> Double -> Int
movie card ticket perc = 4
-- main :: IO ()
-- main = undefined
Expected behavior: Useful error message.
Actual behavior: "panic" error message.
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | GHCi |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |