#10622: Rename Backpack packages to units -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: backpack Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: Phab:D1057 -------------------------------------+------------------------------------- Comment (by simonpj): This sounds plausible to me, though as usual with cabal/backpack I am not 100% sure of my ground. I think of it like this: * Cabal concerns itself with Cabal packages (units of distribution and versioning), including choosing version numbers, downloading them, and figuring out if that particular package (instantiated with its transitive dependencies) is already installed. * GHC concerns itself with Backpack units. Both share a single "installed package database". But they use it in a different way. For GHC at least, it's just a cache: a place to record the result of previous work (including typechecking indefinite packages), so that we don't need to repeat it. There is no harm in repeating it, but it's a waste of time. So Cabal need never see the previously-compiled indefinite packages; they are just a way for GHC to save time. Maybe that is what you are saying. Another way to attack this is to ask "what questions does Cabal ask the installed package database?" and "what questions does GHC ask?". I think the two are different. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10622#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler