From taking a look at FLKAutoLayout
it looks like your problem is with this line in NSLayoutConstraint+FLKAutoLayoutDebug.m :
`return [description stringByAppendingFormat:@" %@ (%@, %@)", asciiArtDescription, [self.firstItem flk_nameTag], [self.secondItem flk_nameTag]];`
asciiArtDescription
is a private method on NSLayoutConstraint, while flk_nameTag
is an property added as an "associated object".
Are you working in Swift? It could be something interfering with the program's ability to do those two things, even though it's in objective-C code. You could try creating a test project in Objective C that recreates the warnings to see if they appear.