#13854: the 'impossible' happened initTc: unsolved constraints -------------------------------------+------------------------------------- Reporter: bitemyapp | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{ [7 of 7] Compiling Texas.Api.OrderItems ( src/Texas/Api/OrderItems.hs, interpreted ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] OrderItemModified_a1mbC :: t_a1mbB[tau:1] (CHoleCan: OrderItemModified) [W] val_a1mbH :: t_a1mbG[tau:1] (CHoleCan: val) [W] runAccountDB_a1md0 :: t_a1mcZ[tau:1] (CHoleCan: runAccountDB) [W] getOrderItemsByOrderId_a1mdb :: t_a1mda[tau:1] (CHoleCan: getOrderItemsByOrderId)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} I have what I believe is a repro of this error, albeit slightly different, located here: https://github.com/bitemyapp/panic-repro-initTc-unsolved- constraints {{{ [3 of 3] Compiling Lib ( src/Lib.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.2.0/build/Lib.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] over_amEW :: t_amEV[tau:1] (CHoleCan: over) [W] ix_amF5 :: t_amF4[tau:1] (CHoleCan: ix)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} This is the error I get there. If I learn more in the process of fixing the original code, I'll report it here. This panic occurs w/ GHC and GHCi. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13854 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler