#13729: ghc does not pick up TH changes across package boundaries -------------------------------------+------------------------------------- Reporter: Feuerbach | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I have the following three modules: {{{#!hs module Types where data Foo = Bar }}} {{{#!hs {-# LANGUAGE TemplateHaskell #-} module TH where import Language.Haskell.TH import Language.Haskell.TH.Syntax import Types th_string = lift . show =<< reify ''Foo }}} {{{#!hs {-# LANGUAGE TemplateHaskell #-} module Main where import TH main = putStrLn $(th_string) }}} The goal is to make Main recompile if the definition of Types.Foo changes. If I simply put the three files in the same directory and compile with ghc, it works. However, if I put Types and TH in package A and Main in package B, then ghc doesn't recompile B.Main if I change the definition of A.Types.Foo and reinstall the package A. I tried this with both stack and cabal-install. In both cases I compiled B.Main directly with ghc, so it's not Cabal that's hiding the changes. If I pass -fforce-recomp to ghc, Main recompiles as expected. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13729 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler