#14102: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: pmckelvy | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.2 Resolution: fixed | Keywords: Operating System: MacOS X | Architecture: x86_64 Type of failure: Compile-time | (amd64) crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed * milestone: => 8.2.1 Old description:

(GHC version 8.0.2 for x86_64-apple-darwin): initTc: unsolved constraints WC {wc_insol = [W] action_a1Ei :: t_a1Eh[tau:1] (CHoleCan: action)}

******* code ******** import Data.Char import Data.List

data InvoiceStruct = InvoiceStruct { total :: Int , shippedItemCount :: Int } deriving (Show)

invoice :: InvoiceStruct -> String -> Int -> InvoiceStruct invoice i comp val = (action) i[total] val

New description: {{{ (GHC version 8.0.2 for x86_64-apple-darwin): initTc: unsolved constraints WC {wc_insol = [W] action_a1Ei :: t_a1Eh[tau:1] (CHoleCan: action)} }}} Code: {{{#!hs import Data.Char import Data.List data InvoiceStruct = InvoiceStruct { total :: Int , shippedItemCount :: Int } deriving (Show) invoice :: InvoiceStruct -> String -> Int -> InvoiceStruct invoice i comp val = (action) i[total] val }}} -- Comment: Thanks for your report! This fails with the expected errors under 8.2.1, {{{ hi.hs:1:1: error: The IO action ‘main’ is not defined in module ‘Main’ | 1 | import Data.Char | ^ hi.hs:10:23: error: Variable not in scope: action :: Main.InvoiceStruct -> [Main.InvoiceStruct -> Int] -> Int -> Main.InvoiceStruct | 10 | invoice i comp val = (action) i[total] val | ^^^^^^ }}} It's not entirely clear what fixed this but it's unlikely that we will release a 8.0.3 so I'm going to close this for now. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14102#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler