Add preExistingPkgs to plan-nix based on plan.json

Author: hamishmack

modules/component-driver.nix

@@ -10,6 +10,11 @@ let
 in
 
 {
+  # Packages in that are `pre-existing` in the cabal plan
+  options.preExistingPkgs = lib.mkOption {
+    type = lib.types.listOf lib.types.str;
+    default = [];
+  };
   # This has a slightly modified option type. We will *overwrite* any previous
   # setting of nonRelocatablePkgs, instead of merging them.  Otherwise you
   # have no chance of removing packages retroactively.  We might improve this

nix-tools/flake.lock

@@ -85,7 +85,7 @@ plan2nix args Plan { packages, extras, components, compilerVersion, compilerPack
   -- called from the toplevel project directory.
   cwd <- getCurrentDirectory
   extrasNix <- fmap (mkNonRecSet  . concat) . forM (Map.toList extras) $ \case
-    (_name, Just (Package v flags (Just (LocalPath folder)) False)) ->
+    (_name, Just (Package v flags (Just (LocalPath folder)) False _)) ->
       do cabalFiles <- findCabalFiles (argHpackUse args) folder
          forM cabalFiles $ \cabalFile ->
            let pkg = cabalFilePkgName cabalFile
@@ -95,7 +95,7 @@ plan2nix args Plan { packages, extras, components, compilerVersion, compilerPack
            in do createDirectoryIfMissing True (takeDirectory nixFile)
                  writeDoc nixFile . prettyNix =<< cabal2nix True (argDetailLevel args) src cabalFile
                  return $ fromString pkg $= mkPath False nix
-    (_name, Just (Package v flags (Just (DVCS (Git url rev) subdirs)) False)) ->
+    (_name, Just (Package v flags (Just (DVCS (Git url rev) subdirs)) False _)) ->
       fmap concat . forM subdirs $ \subdir ->
       do cacheHits <- liftIO $ cacheHits (argCacheFile args) url rev subdir
          case cacheHits of
@@ -109,11 +109,14 @@ plan2nix args Plan { packages, extras, components, compilerVersion, compilerPack
                return $ fromString pkg $= mkPath False nix
     _ -> return []
   let flags = concatMap (\case
-          (name, Just (Package _v f _hasDescriptionOverride _)) -> flags2nix name f
+          (name, Just (Package _v f _hasDescriptionOverride _ _)) -> flags2nix name f
           _ -> []) $ Map.toList extras
       -- Set the `planned` option for all components in the plan.
       planned = map (\name -> name <> ".planned" $=
         ("lib" @. "mkOverride" @@ mkInt 900 @@ mkBool True)) $ Set.toList components
+      preExisting = concatMap (\case
+          (name, Just (Package _ _ _ _ True)) -> [mkStr name]
+          _ -> []) $ Map.toList packages
 
   return $ mkNonRecSet [
     "pkgs" $= ("hackage" ==> mkNonRecSet
@@ -126,7 +129,10 @@ plan2nix args Plan { packages, extras, components, compilerVersion, compilerPack
       ])
     , "extras" $= ("hackage" ==> mkNonRecSet [ "packages" $= extrasNix ])
     , "modules" $= mkList [
-        mkParamset [("lib", Nothing)] True ==> mkNonRecSet [ "packages" $= mkNonRecSet flags ]
+        mkNonRecSet [
+          "preExistingPkgs" $= mkList preExisting
+        ]
+      , mkParamset [("lib", Nothing)] True ==> mkNonRecSet [ "packages" $= mkNonRecSet flags ]
       , mkParamset [("lib", Nothing)] True ==> mkNonRecSet [ "packages" $= mkNonRecSet planned ]
       ]
     ]
@@ -200,6 +206,7 @@ value2plan plan = Plan { packages, components, extras, compilerVersion, compiler
           . KeyMap.toList $ KeyMap.mapMaybe (^? _Bool) $ pkg ^. key "flags" . _Object
       , packageSrc      = Nothing
       , packageHasDescriptionOverride = isJust (pkg ^? key "pkg-cabal-sha256")
+      , packagePreExisting = False
       }
 
     (_, "inplace") -> Just $ Package
@@ -208,6 +215,7 @@ value2plan plan = Plan { packages, components, extras, compilerVersion, compiler
           . KeyMap.toList $ KeyMap.mapMaybe (^? _Bool) $ pkg ^. key "flags" . _Object
       , packageSrc      = Nothing
       , packageHasDescriptionOverride = isJust (pkg ^? key "pkg-cabal-sha256")
+      , packagePreExisting = False
       }
     -- Until we figure out how to force Cabal to reconfigure just about any package
     -- this here might be needed, so that we get the pre-existing packages as well.
@@ -220,6 +228,7 @@ value2plan plan = Plan { packages, components, extras, compilerVersion, compiler
       , packageFlags    = Map.empty
       , packageSrc      = Nothing
       , packageHasDescriptionOverride = isJust (pkg ^? key "pkg-cabal-sha256") -- likely this is always false
+      , packagePreExisting = True
       }
     _ -> Nothing
 

nix-tools/nix-tools/plan2nix/Plan2Nix.hs

@@ -47,4 +47,5 @@ data Package = Package
   , packageFlags :: HashMap VarName Bool
   , packageSrc :: Maybe PkgSrc
   , packageHasDescriptionOverride :: Bool
+  , packagePreExisting :: Bool
   } deriving (Show)