#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 ezyang):
Now we are relying on the package-db ordering on the command line for dependency safety, whereas previously we could check because we had the ABIs of the dependencies.
Yes, you are right. :(
The idea of a package DB "stack" was really just a temporary situation to deal with the fact that we couldn't link multiple package instances into the same binary so we had to have some way to resolve conflicts; my intention was that eventually the idea of a "stack" would just go away when it wasn't necessary any more.
And this is what I get for not being involved in the initial discussion ;) But it is hard for me to see how you could actually do this, because you can always end up in a situation where you have two separate packages with the same symbol name, and now you have to pick one.
In the short term, would anything go wrong if we allowed an IPID anywhere in the stack to satisfy a dependency provided it was unique? And if a dependency is not unique, we resolve in the current way, using the DB ordering.
Nothing wrong! It just sounds really annoying to implement. ;) (I guess... we do a pre-pass to figure out conflicts, and then run the shadowing algorithm?) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12485#comment:20 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler