#14128: Possible bug in Renamer when dealing with orphans -------------------------------------+------------------------------------- Reporter: Shayan-Najd | Owner: bgamari Type: bug | Status: new Priority: normal | Milestone: 8.2.2 Component: Compiler (Type | Version: 8.2.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): It seems like there is a bit of inconsistency regarding whether or not a module can be in its own `dep_orphs`. `TcRnDriver.tcRnImports` seems to suggest that `imp_orphs` (from which `DsUsage.mkDependencies` derives `dep_orphs`) can contain the current module due to `hs-boot`s, {{{#!hs -- Load any orphan-module (including orphan family -- instance-module) interfaces, so that their rules and -- instance decls will be found. But filter out a -- self hs-boot: these instances will be checked when -- we define them locally. -- (We don't need to load non-orphan family instance -- modules until we either try to use the instances they -- define, or define our own family instances, at which -- point we need to check them for consistency.) ; loadModuleInterfaces (text "Loading orphan modules") (filter (/= this_mod) (imp_orphs imports)) }}} However, the assertion in `RnNames.calculateAvails` (which is what Shayan reports) obvious disagrees: {{{#!hs orphans | orph_iface = ASSERT2( not (imp_sem_mod `elem` dep_orphs deps), ppr imp_sem_mod <+> ppr (dep_orphs deps) ) imp_sem_mod : dep_orphs deps }}} Looking at `mkDependendies`, it seems that we explicitly filter the currently module out of `imp_dep_mods`, {{{#!hs let dep_mods = modDepsElts (delFromUFM (imp_dep_mods imports) (moduleName mod)) -- M.hi-boot can be in the imp_dep_mods, but we must remove -- it before recording the modules on which this one depends! -- (We want to retain M.hi-boot in imp_dep_mods so that -- loadHiBootInterface can see if M's direct imports depend -- on M.hi-boot, and hence that we should do the hi-boot consistency -- check.) }}} We do not do the same thing for `dep_orphs`; I wonder if this should change. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14128#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler