#12485: -package-db flags now need to be sorted by dependency order -------------------------------------+------------------------------------- Reporter: niteria | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.3 Component: Package system | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): phab:D2450, Wiki Page: | phab:D2514 -------------------------------------+------------------------------------- Comment (by simonmar): Ok, I'm still trying to get my head around this problem. Here's the algorithm I want to use: * for each package DB * add packages one by one to an accumulating `Map PackageId (Maybe Package)` * if we encounter a `PackageKey` that we already have: * If the ABIs are the same, replace the old one by the new one * If the ABIs are different, insert a `Nothing` entry in the map (and report an error with -v2) * If we already have a `Nothing` for this `PackageKey`, leave it as `Nothing` (and report an error with -v2) * Afterwards, remove any package from the DB with one or more missing dependencies, recursively until you can remove no more packages. (report what we're doing with -v2) Does anything go wrong with this? It's a slight variant of the algorithm that we used before `PackageKey`s I think. When we have dependencies that specify ABIs we can refine this to be more intelligent about what to throw away, but in the meantime I think this will be fine. It's very similar to what we used to do. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12485#comment:28 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler