#9896: panic: wrongKindOfFamily -------------------------------------+------------------------------------- Reporter: luite | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by jstolarek): A simple fix for this can go into the `Parser.y` by changing second production in `at_decl_inst` from: {{{ -- data/newtype instance declaration | data_or_newtype capi_ctype tycl_hdr constrs deriving {% amms (mkDataFamInst (comb4 $1 $3 $4 $5) (snd $ unLoc $1) $2 $3 Nothing (reverse (snd $ unLoc $4)) (unLoc $5)) ((fst $ unLoc $1):(fst $ unLoc $4)) } }}} to {{{ -- data/newtype instance declaration | 'data' capi_ctype tycl_hdr constrs deriving {% amms (mkDataFamInst (comb4 $1 $3 $4 $5) DataType $2 $3 Nothing (reverse (snd $ unLoc $4)) (unLoc $5)) ((mj AnnData $1):(fst $ unLoc $4)) } }}} Then your definition would be rejected as a parse error. However, on my branch this change drastically increases the number of reduce/reduce conflicts so perhaps a different solution would be better. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9896#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler