trying to build an Xcode 4.0 project using qmake 4.8 crashes Xcode 4

1/ created an app project using 4.8 on OS Mac Lion with QT 4.8... works fine

now trying to have an Xcode 4 project...

2/ running QtSDK/Desktop/Qt/4.8.0/gcc/bin/qmake -spec macx-xcode project.pro

everything went fine no error

3/ trying to open the proj.xcodeproj generated with Xcode

xcode 4 cannot open and crash with the following message

ASSERTION FAILURE in /SourceCache/IDEXcode3ProjectSupport/IDEXcode3ProjectSupport-613/Xcode3Sources/XcodeIDE/Frameworks/DevToolsBase/pbxcore/Target.subproj/PBXTarget.m:1959
Details: configName should be a non-empty string, but it is nil
Object: <PBXNativeTarget: 0x401617fe0>
Method: -cachedPropertyExpansionContextForWorkspaceArenaSnapshot:configurationNamed:
Thread: <NSThread: 0x40010a260>

Hints: None
Backtrace:
0 0x000000010c315f1a -[IDEAssertionHandler handleFailureInMethod:object:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
1 0x000000010b9c5304 _DVTAssertionFailureHandler (in DVTFoundation)
2 0x000000010fc027db -[PBXTarget cachedPropertyExpansionContextForWorkspaceArenaSnapshot:configurationNamed:] (in DevToolsCore)
3 0x000000010fc06e60 -[PBXTarget packageTypeForConfigurationNamed:] (in DevToolsCore)
4 0x000000010fc5e1c6 -[PBXNativeTarget productReferenceIsExecutable] (in DevToolsCore)
5 0x000000010fc08512 -[PBXTarget _updateExecutables] (in DevToolsCore)
6 0x000000010fbd25b4 -[PBXProject _unarchiverDidFinishUnarchiving:] (in DevToolsCore)
7 0x00007fff8e340716 __-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_1 (in Foundation)
8 0x00007fff8bd2c51a _CFXNotificationPost (in CoreFoundation)
9 0x00007fff8e32c9cb -[NSNotificationCenter postNotificationName:object:userInfo:] (in Foundation)
10 0x000000010fbeb608 -[PBXPListUnarchiver decodeRootObject] (in DevToolsCore)
11 0x000000010fbbf2f5 +[PBXProject projectWithFile:errorHandler:readOnly:] (in DevToolsCore)
12 0x000000010fd76eef -[Xcode3Project initWithFilePath:extension:error:] (in DevToolsCore)
13 0x000000010bea5ef6 __63+[IDEContainer retainedContainerAtFilePath:fileDataType:error:]_block_invoke_0 (in IDEFoundation)
14 0x000000010b9637f9 __38-[DVTDispatchLock performLockedBlock:]_block_invoke_0 (in DVTFoundation)
15 0x00007fff90a30afd _dispatch_barrier_sync_f_invoke (in libdispatch.dylib)
16 0x000000010b9637a9 -[DVTDispatchLock performLockedBlock:] (in DVTFoundation)
17 0x000000010bea4e34 +[IDEContainer retainedContainerAtFilePath:fileDataType:error:] (in IDEFoundation)
18 0x000000010c225317 -[IDEDocumentController _openProjectsAndWorkspaces:documents:simpleFileURLs:display:error:] (in IDEKit)
19 0x000000010c2250eb -[IDEDocumentController _openDocumentsForURLs:display:error:] (in IDEKit)
20 0x000000010c30eeb1 -[IDEApplicationController _openFiles:] (in IDEKit)
21 0x00007fff84d2a4c2 __-[NSApplication(NSAppleEventHandling) _handleAEOpenDocumentsForURLs:]_block_invoke_1 (in AppKit)
22 0x00007fff84a72cbb __-[NSDocumentController(NSInternal) _autoreopenDocumentsWithCompletionHandler:]_block_invoke_2 (in AppKit)
23 0x00007fff84a7290f -[NSDocumentController(NSInternal) _autoreopenDocumentsWithCompletionHandler:] (in AppKit)
24 0x00007fff84aa1cf2 -[NSPersistentUIManager finishedRestoringWindowsWithZOrder:registerAsReady:completionHandler:] (in AppKit)
25 0x00007fff84a9f21f -[NSPersistentUIManager restoreAllPersistentStateWithTalagentWindows:registeringAsReadyWhenDone:completionHandler:] (in AppKit)
26 0x00007fff84cb2bd5 -[NSApplication(NSAppleEventHandling) _handleAEOpenDocumentsForURLs:] (in AppKit)
27 0x00007fff84a71f9a -[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] (in AppKit)
28 0x00007fff8bd75f51 -[NSObject performSelector:withObject:withObject:] (in CoreFoundation)
29 0x00007fff8e3631c7 __-[NSAppleEventManager setEventHandler:andSelector:forEventClass:andEventID:]_block_invoke_1 (in Foundation)
30 0x00007fff8e36214e -[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] (in Foundation)
31 0x00007fff8e361fdc _NSAppleEventManagerGenericHandler (in Foundation)
32 0x000000010c30f373 HandleOpenDocAE (in IDEKit)
33 0x00007fff88743a85 aeDispatchAppleEvent(AEDesc const*, AEDesc*, unsigned int, unsigned char*) (in AE)
34 0x00007fff88743963 ZL25dispatchEventAndSendReplyPK6AEDescPS (in AE)
35 0x00007fff88743857 aeProcessAppleEvent (in AE)
36 0x00007fff8df9a12d AEProcessAppleEvent (in HIToolbox)
37 0x00007fff84a6f3dd _DPSNextEvent (in AppKit)
38 0x00007fff84a6ea95 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] (in AppKit)
39 0x00007fff84a6b3d6 -[NSApplication run] (in AppKit)
40 0x00007fff84ce952a NSApplicationMain (in AppKit)
41 0x000000010b95eeec (in Xcode)