#731: Custom Build-type with --package-db and --global encounters runtime error ---------------------------------+------------------------------------------ Reporter: cygnus | Owner: Type: defect | Status: new Priority: normal | Milestone: Component: cabal-install tool | Version: 1.8.0.4 Severity: normal | Keywords: Difficulty: unknown | Ghcversion: 6.12.2 Platform: Linux | ---------------------------------+------------------------------------------ To reproduce: * Run `cabal init`, change `Build-type` to `Custom` (`Setup.hs` already provided by `cabal init`) * Run `ghc-pkg init db` * Run `cabal configure --package-db=./db --global` * Output: {{{ Resolving dependencies... cabal: internal error: unexpected package db stack }}} In `cabal-install-0.8.2`, this appears to be caused by the code on lines 112-114 of `Distribution.Client.Configure`: {{{ usePackageDB = if UserPackageDB `elem` packageDBs then packageDBs else packageDBs ++ [UserPackageDB] }}} in combination with the code on lines 297-306 of `Distribution.Client.SetupWrapper`: {{{ ghcPackageDbOptions :: PackageDBStack -> [String] ghcPackageDbOptions dbstack = case dbstack of (GlobalPackageDB:UserPackageDB:dbs) -> concatMap specific dbs (GlobalPackageDB:dbs) -> "-no-user-package-conf" : concatMap specific dbs _ -> ierror where specific (SpecificPackageDB db) = [ "-package-conf", db ] specific _ = ierror ierror = error "internal error: unexpected package db stack" }}} Essentially, the order of the package databases in the stack is not as expected since the list already contains a `SpecificPackageDB` when the `UserPackageDB` is appended. (Note: this applies to GHC 6.12.3 and Cabal 1.8.0.6 on my system, but I could not select those versions in the ticket properties.) -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/731 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects