Got this error when running MacVim under Yosemite:

Unable to simultaneously satisfy constraints:
(
    "<NSAutoresizingMaskLayoutConstraint:0x7fe499dcde70 h=--& v=--& V:[FI_TBrowserBackgroundView:0x7fe49c5793a0(0)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe49c4146e0 h=-&- v=-&- V:|-(0)-[FI_TListScrollView:0x7fe499df0480]   (Names: '|':FI_TBrowserBackgroundView:0x7fe49c5793a0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe49c4070c0 h=-&- v=-&- V:|-(0)-[NSClipView:0x7fe499df00d0]   (Names: '|':FI_TListScrollView:0x7fe499df0480 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe499e0d2b0 h=-&- v=-&- V:[NSClipView:0x7fe499df00d0]-(0)-|   (Names: '|':FI_TListScrollView:0x7fe499df0480 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe49c414690 h=-&- v=-&- V:[FI_TListScrollView:0x7fe499df0480]-(0)-|   (Names: '|':FI_TBrowserBackgroundView:0x7fe49c5793a0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe499ed8290 h=-&- v=-&- V:[FI_TListView:0x7fe499defad0]-(17)-|   (Names: '|':NSClipView:0x7fe499df00d0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe499ed8240 h=-&- v=-&- V:|-(0)-[FI_TListView:0x7fe499defad0]   (Names: '|':NSClipView:0x7fe499df00d0 )>"
)

Will attempt to recover by breaking constraint 
<NSAutoresizingMaskLayoutConstraint:0x7fe499ed8290 h=-&- v=-&- 
V:[FI_TListView:0x7fe499defad0]-(17)-|   (Names: '|':NSClipView:0x7fe499df00d0 
)>

Set the NSUserDefault 
NSConstraintBasedLayoutVisualizeMutuallyExclusiveConstraints to YES to have 
-[NSWindow visualizeConstraints:] automatically called when this happens.  
And/or, break on objc_exception_throw to catch this in the debugger.