#10934: Iface type variable out of scope -------------------------------------+------------------------------------- Reporter: mjmrotek | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: interface | Operating System: Linux Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | -------------------------------------+------------------------------------- I'm sorry for spamming code and not providing a distilled example, but honestly I have no idea how to even begin pinpointing this. I'm writing a library and hosting it on Github: https://github.com/marcinmrotek/pipes-key-value-csv which compiles fine, but when I try to compile the test suite, GHC crashes with this error message: {{{ /home/marcin/haskell/pipes-key-value-csv/.stack- work/dist/x86_64-linux/Cabal-1.22.4.0/build/Pipes/KeyValueCsv/Internal/KeyValue.hi Declaration for $fFromKeyValuesf:3: Iface type variable out of scope: k Cannot continue after interface file error }}} when I uncomment the {{{#!hs . KV.foldHeader }}} line in https://github.com/marcinmrotek/pipes-key-value- csv/blob/master/test/Test/KeyValue.hs The thing is, this function does not even use the "FromKeyValues" type class mentioned - https://github.com/marcinmrotek/pipes-key-value- csv/blob/master/src/Pipes/KeyValueCsv/Internal/KeyValue.hs KV.parseLine, which does, compiles fine (the test suite runs and fails with "Prelude: undefined". They're both defined here: https://github.com/marcinmrotek/pipes-key-value- csv/blob/master/src/Pipes/KeyValueCsv/KeyValue.hs I've tried "stack clean", reinstalling both GHC and stack, installing my package globally with cabal-install (although I had to fix the validation-0.5.1 package by removing the Safe pragma; I've tried to use stack again, pointing it to the exact same code for validation-0.5.1, to no avail), the result is always the same - the library compiles, the test suite doesn't. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10934 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler