lucascorrea/debug_constraints.md

## debug_constraints.md

      
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              debug_constraints.md
            
          
    You'll want to add a Symbolic Breakpoint. Apple provides an excellent guide on how to do this.
1 Open the Breakpoint Navigator cmd+7
2 Click the Add button in the lower left
3 Select Add Symbolic Breakpoint...
4 Where it says Symbol just type in UIViewAlertForUnsatisfiableConstraints
Add action expression below

Obj-C project

po [[UIWindow keyWindow] _autolayoutTrace]

Swift project

expr -l objc++ -O -- [[UIWindow keyWindow] _autolayoutTrace]


###Change color object error
expr ((UIView *)0x7f88a8cc2050).backgroundColor = [UIColor redColor]
http://stackoverflow.com/questions/26389273/how-to-trap-on-uiviewalertforunsatisfiableconstraints