#13318: ghc-7.10.1 panics when compiling singletons-1.1.2.1 -------------------------------------+------------------------------------- Reporter: WrenThornton | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 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: -------------------------------------+------------------------------------- Not sure if this has been fixed in newer versions or not, but: {{{ [39 of 45] Compiling Data.Singletons.Prelude.List ( src/Data/Singletons/Prelude/List.hs, dist/build/Data/Singletons/Prelude/List.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.1 for x86_64-apple-darwin): Template variable unbound in rewrite rule n_X2iZh [a_a2gBn, t_a2gBo, n_a2iB7, ipv_s2szc, ipv_s2szd, sc_s2tXD, sc_s2tXF, sc_s2tXG, sg_s2tXH] [a_X2gZv, t_X2gZx, n_X2iZh, ipv_X2sXn, ipv_X2sXp, sc_X2ulQ, sc_X2ulT, sc_X2ulV, sg_X2ulX] [TYPE a_a2gBn, TYPE t_a2gBo, TYPE Let1627878522XsSym4 t_a2gBo n_a2iB7 ipv_s2szc ipv_s2szd, sc_s2tXD, (SCons @ a_a2gBn @ (ipv_s2szc : ipv_s2szd) @ ipv_s2szc @ ipv_s2szd @~ _N sc_s2tXF sc_s2tXG) `cast` (sg_s2tXH :: R:Sing[]z (ipv_s2szc : ipv_s2szd) ~R# Sing (Apply (Apply (:$) ipv_s2szc) ipv_s2szd))] [TYPE a_a2gBn, TYPE t_a2gBo, TYPE Let1627878522XsSym4 t_a2gBo ipv_s2szc ipv_X2sQZ ipv_X2sR1, sc_s2tXD, (SCons @ a_a2gBn @ (ipv_X2sQZ : ipv_X2sR1) @ ipv_X2sQZ @ ipv_X2sR1 @~ _N ipv_s2szf ipv_s2szg) `cast` (Sub (Sym (TFCo:R:Sing[]z[0] _N)) (Sym (TFCo:R:Apply[][]:$$l0[0] _N _N _N) ; (Apply (Sym (TFCo:R:Apply(->)k:$l0[0] _N _N)) _N)_N) :: R:Sing[]z (ipv_X2sQZ :$$$ ipv_X2sR1) ~R# Sing (Apply (Apply (:$) ipv_X2sQZ) ipv_X2sR1))] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13318 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler