WIP

cabal-install/src/Distribution/Client/SetupWrapper.hs

@@ -647,7 +647,12 @@ getExternalSetupMethod verbosity options pkgId bt = do
       ++ show (useDependenciesExclusive options)
   createDirectoryIfMissingVerbose verbosity True setupDir
 
-  (cabalLibVersion, mCabalLibInstalledPkgId, options') <- cabalLibVersionToUse verbosity options pkgId bt
+  let SetupPaths {setupHs} = getSetupPaths options
+  (cabalLibVersion, mCabalLibInstalledPkgId, options') <-
+    cabalLibVersionToUse verbosity options pkgId bt
+     (updateSetupScript verbosity (workingDir options) setupHs bt)
+     (writeSetupVersionFile options)
+
   debug verbosity $ "Using Cabal library version " ++ prettyShow cabalLibVersion
 
   path <-
@@ -707,33 +712,45 @@ cabalLibVersionToUse
   -> SetupScriptOptions
   -> PackageId
   -> BuildType
+  -> (Version -> IO ())
+  -> (Version -> IO ())
   -> IO (Version, Maybe ComponentId, SetupScriptOptions)
-cabalLibVersionToUse verbosity options pkgId bt =
+cabalLibVersionToUse verbosity options pkgId bt  updateSetupScript' writeSetupVersionFile' =
     case find (isCabalPkgId . snd) (useDependencies options) of
       Just (unitId, pkgId') -> do
         let version = pkgVersion pkgId'
-        updateSetupScript verbosity (workingDir options) setupHs version bt
-        writeSetupVersionFile options version
+        updateSetupScript' version
+        writeSetupVersionFile' version
         return (version, Just unitId, options)
       Nothing ->
         case useCabalSpecVersion options of
           Just version -> do
-            updateSetupScript verbosity (workingDir options) setupHs version bt
-            writeSetupVersionFile options version
+            updateSetupScript' version
+            writeSetupVersionFile' version
             return (version, Nothing, options)
           Nothing -> do
             savedVer <- readSetupVersionFile options
+
+            let installedVersion = do
+                    let SetupScriptOptions{useCompiler, usePlatform, useProgramDb, usePackageIndex, usePackageDB} = options
+                    (_comp, _platform, _progdb, index) <- configureCompiler verbosity useCompiler usePlatform useProgramDb usePackageIndex usePackageDB
+                    let options' = options{usePackageIndex = Just index}
+                    (version', mipkgid) <- installedCabalVersion verbosity index (useCabalVersion options') pkgId bt
+                    updateSetupScript' version'
+                    writeSetupVersionFile' version'
+                    return (version', mipkgid, options')
+
             case savedVer of
-              Just version | version `withinRange` useCabalVersion options ->
-                do
-                  updateSetupScript verbosity (workingDir options) setupHs version bt
-                  -- Does the previously compiled setup executable
-                  -- still exist and is it up-to date?
-                  useExisting <- canUseExistingSetup version
-                  if useExisting
-                    then return (version, Nothing, options)
-                    else installedVersion verbosity options pkgId bt
-              _ -> installedVersion verbosity options pkgId bt
+              Just version | version `withinRange` useCabalVersion options -> do
+                updateSetupScript' version
+                -- Does the previously compiled setup executable still exist and is it up-to date?
+                useExisting <- canUseExistingSetup version
+                if useExisting
+                  then return (version, Nothing, options)
+                  else installedVersion
+
+              _ -> installedVersion
+
     where
     SetupPaths {..} = getSetupPaths options
     -- This check duplicates the checks in 'getCachedSetupExecutable' /
@@ -767,23 +784,6 @@ readSetupVersionFile options = do
   where 
     SetupPaths {..} = getSetupPaths options
 
-installedVersion
-  :: Verbosity
-  -> SetupScriptOptions
-  -> PackageId
-  -> BuildType
-  -> IO (Version, Maybe InstalledPackageId, SetupScriptOptions)
-installedVersion verbosity options pkgId bt = do
-  let SetupScriptOptions{useCompiler, usePlatform, useProgramDb, usePackageIndex, usePackageDB} = options
-  (_comp, _platform, _progdb, index) <- configureCompiler verbosity useCompiler usePlatform useProgramDb usePackageIndex usePackageDB
-  let options' = options{usePackageIndex = Just index}
-  (version, mipkgid) <- installedCabalVersion verbosity index (useCabalVersion options') pkgId bt
-  updateSetupScript verbosity (workingDir options') setupHs version bt
-  writeSetupVersionFile options' version
-  return (version, mipkgid, options')
-  where
-    SetupPaths{..} = getSetupPaths options
-
 installedCabalVersion
   :: Verbosity
   -> InstalledPackageIndex
@@ -840,10 +840,10 @@ updateSetupScript
   -- ^ Working directory
   -> FilePath
   -- ^ Path to Setup.hs
-  -> Version
   -> BuildType
+  -> Version
   -> IO ()
-updateSetupScript verbosity workdir setupHs _cabalLibVersion Custom = do
+updateSetupScript verbosity workdir setupHs Custom _cabalLibVersion = do
   useHs <- doesFileExist customSetupHs
   useLhs <- doesFileExist customSetupLhs
   unless (useHs || useLhs) $
@@ -857,7 +857,7 @@ updateSetupScript verbosity workdir setupHs _cabalLibVersion Custom = do
   where
     customSetupHs = workdir </> "Setup.hs"
     customSetupLhs = workdir </> "Setup.lhs"
-updateSetupScript verbosity _workdir setupHs cabalLibVersion bt =
+updateSetupScript verbosity _workdir setupHs bt cabalLibVersion =
   rewriteFileLBS verbosity setupHs (buildTypeScript cabalLibVersion bt)
 
 buildTypeScript :: Version -> BuildType -> BS.ByteString