diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/main/Packages.hs | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/compiler/main/Packages.hs b/compiler/main/Packages.hs index 28f2f2d2c3..db48d99bac 100644 --- a/compiler/main/Packages.hs +++ b/compiler/main/Packages.hs @@ -367,13 +367,15 @@ readPackageConfig dflags conf_file = do proto_pkg_configs <- if isdir - then do let filename = conf_file </> "package.cache" - debugTraceMsg dflags 2 (text "Using binary package database:" <+> text filename) - readPackageDbForGhc filename + then readDirStylePackageConfig conf_file else do isfile <- doesFileExist conf_file if isfile - then throwGhcExceptionIO $ InstallationError $ + then do + mpkgs <- tryReadOldFileStylePackageConfig + case mpkgs of + Just pkgs -> return pkgs + Nothing -> throwGhcExceptionIO $ InstallationError $ "ghc no longer supports single-file style package " ++ "databases (" ++ conf_file ++ ") use 'ghc-pkg init' to create the database with " ++ @@ -388,6 +390,31 @@ readPackageConfig dflags conf_file = do pkg_configs2 = setBatchPackageFlags dflags pkg_configs1 -- return pkg_configs2 + where + readDirStylePackageConfig conf_dir = do + let filename = conf_dir </> "package.cache" + debugTraceMsg dflags 2 (text "Using binary package database:" <+> text filename) + readPackageDbForGhc filename + + -- Single-file style package dbs have been deprecated for some time, but + -- it turns out that Cabal was using them in one place. So this is a + -- workaround to allow older Cabal versions to use this newer ghc. + -- We check if the file db contains just "[]" and if so, we look for a new + -- dir-style db in conf_file.d/, ie in a dir next to the given file. + -- We cannot just replace the file with a new dir style since Cabal still + -- assumes it's a file and tries to overwrite with 'writeFile'. + -- ghc-pkg also cooperates with this workaround. + tryReadOldFileStylePackageConfig = do + content <- readFile conf_file `catchIO` \_ -> return "" + if take 2 content == "[]" + then do + let conf_dir = conf_file <.> "d" + direxists <- doesDirectoryExist conf_dir + if direxists + then do debugTraceMsg dflags 2 (text "Ignoring old file-style db and trying:" <+> text conf_dir) + liftM Just (readDirStylePackageConfig conf_dir) + else return (Just []) -- ghc-pkg will create it when it's updated + else return Nothing setBatchPackageFlags :: DynFlags -> [PackageConfig] -> [PackageConfig] setBatchPackageFlags dflags pkgs = maybeDistrustAll pkgs |