IDE: checking base packages and on mismatch building IDE using lazbuild

ide/buildlazdialog.pas

@@ -628,7 +628,7 @@ begin
         MakeExe);
       Tool.FreeData:=true;
       Tool.Process.Executable:=LazbuildExe;
-      Tool.Process.Parameters.Add('--user-ide=');
+      Tool.Process.Parameters.Add('--build-ide=');
       Tool.Process.Parameters.Add('--lazarusdir=.');
       Tool.Process.Parameters.Add('--pcp='+GetPrimaryConfigPath);
       Tool.AddParsers(SubToolFPC);

ide/main.pp

@@ -7887,14 +7887,13 @@ begin
     end;
     MainBuildBoss.SetBuildTargetIDE;
 
-    {$IFDEF EnableBuildIDEUsingLazbuild}
     ErrMsg:=PackageGraph.SrcBasePackagesNeedLazbuild;
     if ErrMsg<>'' then
     begin
       r:=IDEQuestionDialog('Major changes detected',
         'The Lazarus sources use a different list of base packages.'+LineEnding
         +'It is recommended to compile the IDE clean using lazbuild.',
-        mtConfirmation,[mrYes,'Clean up + lazbuild',21,'No clean up + lazbuild',mrIgnore,'Compile normally',mrCancel]);
+        mtConfirmation,[mrYes,'Clean up + lazbuild',21,'lazbuild',mrIgnore,'Compile normally',mrCancel]);
       case r of
       mrYes:
         exit(fBuilder.MakeIDEUsingLazbuild(true));
@@ -7905,9 +7904,6 @@ begin
         exit;
       end;
     end;
-    {$ELSE}
-    PackageGraph.ParseBasePackages(false);
-    {$ENDIF}
 
     // clean up
     PkgCompileFlags:=[];

packager/packagesystem.pas

@@ -5129,7 +5129,7 @@ var
 begin
   Result:=false;
   LazDir:=EnvironmentOptions.GetParsedLazarusDirectory;
-  if (LazDir='') or not FilenameIsPascalSource(LazDir) then
+  if (LazDir='') or not FilenameIsAbsolute(LazDir) then
   begin
     if Verbose then
       debugln(['Error: (lazarus) TLazPackageGraph.ParseBasePackages missing LazarusDir "',LazDir,'"']);