#16072: All dependencies of packages must be explicitly listed when defining flavour packages -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 8.6.3 (Hadrian) | 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: -------------------------------------+------------------------------------- In the Hadrian user guide, it explains that you can use the `packages` variable in order to describe what is built. However, unless you list all the dependencies of what you want to build also in `packages` then it will fail to build. For example, if I want to just build `ghctags` then I might try to modify `packages` to {{{ ghcTagsPackages stage = case stage of Stage2 -> [ghcTags] _ -> [] }}} but this will fail as I haven't listed any dependencies of `ghcTags` at all. The culprit here is the `contextDependencies` function. {{{ contextDependencies :: Context -> Action [Context] contextDependencies Context {..} = do depPkgs <- go [package] return [ Context depStage pkg way | pkg <- depPkgs, pkg /= package ] where depStage = min stage Stage1 go pkgs = do deps <- concatMapM step pkgs let newPkgs = nubOrd $ sort (deps ++ pkgs) if pkgs == newPkgs then return pkgs else go newPkgs step pkg = do deps <- pkgDependencies pkg active <- sort <$> stagePackages depStage return $ intersectOrd (compare . pkgName) active deps }}} Notice in the definition of `step`, the actual package dependencies are intersected with `stagePackages`. It is also unclear to me why this function is defined recursively as surely when we `need` one dependency, that will in turn `need` its dependencies and so on. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16072 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler