How can I set CG_CONTEXT_SHOW_BACKTRACE environmental variable?
IosXcodeSwiftCore GraphicsIos Problem Overview
I have three buttons in my view. After setting the cornerRadus in the viewDidLoad() : button.layer.cornerRadius = 20 I get the following error message in the log:
<Error>: CGContextSaveGState: invalid context 0x0.
If you want to see the backtrace, please set
CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Questions:
How can I set CG_CONTEXT_SHOW_BACKTRACE environmental variable?- Or how can I fix this warning?
Okay I've the backtrace now from the message. It doesn't make any sense to me. Some help please...
Aug 7 14:27:00 <Error>: CGContextSaveGState: invalid context 0x0. Backtrace:
<-[UIStatusBarItemView updateContentsAndWidth]+33>
<-[UIStatusBarItemView initWithItem:data:actions:style:]+477>
<+[UIStatusBarItemView createViewForItem:withData:actions:foregroundStyle:]+134>
<-[UIStatusBarLayoutManager _createViewForItem:withData:actions:]+163>
<-[UIStatusBarLayoutManager _prepareEnabledItemType:withEnabledItems:withData:actions:itemAppearing:itemDisappearing:]+36
<-[UIStatusBarLayoutManager prepareEnabledItems:withData:actions:]+92>
<-[UIStatusBarForegroundView _setStatusBarData:actions:animated:]+797>
<-[UIStatusBarForegroundView setStatusBarData:actions:animated:]+332>
<__51-[UIStatusBar _prepareToSetStyle:animation:forced:]_block_invoke+360>
<+[UIView(Animation) performWithoutAnimation:]+65>
<-[UIStatusBar _prepareToSetStyle:animation:forced:]+866>
<-[UIStatusBar _requestStyleAttributes:animationParameters:forced:]+391>
<-[UIStatusBar requestStyle:animationParameters:forced:]+437>
<-[UIStatusBar requestStyle:animated:forced:]+90>
<-[UIStatusBar _evaluateServerRegistration]+250>
<__45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke+590>
<-[UIView(Hierarchy) _postMovedFromSuperview:]+544>
<-[UIView(Internal) _addSubview:positioned:relativeTo:]+1967>
<-[UIStatusBarWindow setStatusBar:]+288>
<-[UIApplication _createStatusBarWithRequestedStyle:orientation:hidden:]+340>
<-[UIApplication _runWithMainScene:transitionContext:completion:]+950>
<-[UIApplication workspaceDidEndTransaction:]+188>
<-[FBSSerialQueue _performNext]+192>
<-[FBSSerialQueue _performNextFromRunLoopSource]+45>
<__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__+17>
<__CFRunLoopDoSources0+556>
<__CFRunLoopRun+867>
<CFRunLoopRunSpecific+488>
<-[UIApplication _run]+402>
<UIApplicationMain+171>
<main+117>
Aug 7 14:27:00 <Error>: CGContextTranslateCTM: invalid context 0x0. Backtrace:
<-[UIStatusBarItemView updateContentsAndWidth]+33>
<-[UIStatusBarItemView initWithItem:data:actions:style:]+477>
<+[UIStatusBarItemView createViewForItem:withData:actions:foregroundStyle:]+134>
<-[UIStatusBarLayoutManager _createViewForItem:withData:actions:]+163>
<-[UIStatusBarLayoutManager _prepareEnabledItemType:withEnabledItems:withData:actions:itemAppearing:itemDisappearing:]+36
<-[UIStatusBarLayoutManager prepareEnabledItems:withData:actions:]+92>
<-[UIStatusBarForegroundView _setStatusBarData:actions:animated:]+797>
<-[UIStatusBarForegroundView setStatusBarData:actions:animated:]+332>
<__51-[UIStatusBar _prepareToSetStyle:animation:forced:]_block_invoke+360>
<+[UIView(Animation) performWithoutAnimation:]+65>
<-[UIStatusBar _prepareToSetStyle:animation:forced:]+866>
<-[UIStatusBar _requestStyleAttributes:animationParameters:forced:]+391>
<-[UIStatusBar requestStyle:animationParameters:forced:]+437>
<-[UIStatusBar requestStyle:animated:forced:]+90>
<-[UIStatusBar _evaluateServerRegistration]+250>
<__45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke+590>
<-[UIView(Hierarchy) _postMovedFromSuperview:]+544>
<-[UIView(Internal) _addSubview:positioned:relativeTo:]+1967>
<-[UIStatusBarWindow setStatusBar:]+288>
<-[UIApplication _createStatusBarWithRequestedStyle:orientation:hidden:]+340>
<-[UIApplication _runWithMainScene:transitionContext:completion:]+950>
<-[UIApplication workspaceDidEndTransaction:]+188>
<-[FBSSerialQueue _performNext]+192>
<-[FBSSerialQueue _performNextFromRunLoopSource]+45>
<__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__+17>
<__CFRunLoopDoSources0+556>
<__CFRunLoopRun+867>
<CFRunLoopRunSpecific+488>
<-[UIApplication _run]+402>
<UIApplicationMain+171>
<main+117>
Aug 7 14:27:00 <Error>: CGContextRestoreGState: invalid context 0x0. Backtrace:
<-[UIStatusBarItemView updateContentsAndWidth]+33>
<-[UIStatusBarItemView initWithItem:data:actions:style:]+477>
<+[UIStatusBarItemView createViewForItem:withData:actions:foregroundStyle:]+134>
<-[UIStatusBarLayoutManager _createViewForItem:withData:actions:]+163>
<-[UIStatusBarLayoutManager _prepareEnabledItemType:withEnabledItems:withData:actions:itemAppearing:itemDisappearing:]+36
<-[UIStatusBarLayoutManager prepareEnabledItems:withData:actions:]+92>
<-[UIStatusBarForegroundView _setStatusBarData:actions:animated:]+797>
<-[UIStatusBarForegroundView setStatusBarData:actions:animated:]+332>
<__51-[UIStatusBar _prepareToSetStyle:animation:forced:]_block_invoke+360>
<+[UIView(Animation) performWithoutAnimation:]+65>
<-[UIStatusBar _prepareToSetStyle:animation:forced:]+866>
<-[UIStatusBar _requestStyleAttributes:animationParameters:forced:]+391>
<-[UIStatusBar requestStyle:animationParameters:forced:]+437>
<-[UIStatusBar requestStyle:animated:forced:]+90>
<-[UIStatusBar _evaluateServerRegistration]+250>
<__45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke+590>
<-[UIView(Hierarchy) _postMovedFromSuperview:]+544>
<-[UIView(Internal) _addSubview:positioned:relativeTo:]+1967>
<-[UIStatusBarWindow setStatusBar:]+288>
<-[UIApplication _createStatusBarWithRequestedStyle:orientation:hidden:]+340>
<-[UIApplication _runWithMainScene:transitionContext:completion:]+950>
<-[UIApplication workspaceDidEndTransaction:]+188>
<-[FBSSerialQueue _performNext]+192>
<-[FBSSerialQueue _performNextFromRunLoopSource]+45>
<__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__+17>
<__CFRunLoopDoSources0+556>
<__CFRunLoopRun+867>
<CFRunLoopRunSpecific+488>
<-[UIApplication _run]+402>
<UIApplicationMain+171>
<main+117>
Ios Solutions
Solution 1 - Ios
You can set an environmental variable via this menu: Product -> Scheme -> Edit Scheme. Under the "Run" item, locate the "Arguments" tab, you'll see "Environmental Variables" in the tab, Add CG_CONTEXT_SHOW_BACKTRACE and set its value to YES.
Solution 2 - Ios
It's a bug in 9b5:
https://forums.developer.apple.com/thread/13683
File a RADAR with Apple.
Solution 3 - Ios
This problem happen with Xcode 7. In my case i removed the UIViewControllerBasedStatusBarAppearance from Info.plist and the problem solved! See the answer in this post:
Solution 4 - Ios
On Xcode 7:
In case you still want the status bar is hidden, just change UIViewControllerBasedStatusBarAppearance in the Info.plist file into View controller-based status bar appearance. Don't forget to set it by NO