lldbのrecursiveDescriptionがめっちゃ便利です。
lldbでUIViewのsubviewを再帰的に確認できます。
(lldb) po [self.view recursiveDescription] <UIView: 0x113713260; frame = (0 0; 320 568); autoresize = RM+BM; layer = <CALayer: 0x10bca42f0>> | <_UILayoutGuide: 0x10bcac7d0; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x11370df90>> | <_UILayoutGuide: 0x10bcb0650; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x10bc257b0>> | <UIProgressView: 0x10bf59360; frame = (48 198.8; 224 2); opaque = NO; layer = <CALayer: 0x10bf5cf70>> | | <UIImageView: 0x10be348e0; frame = (0 0; 160 2); clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x10be24e50>> | | | <CAGradientLayer: 0x10be2d800> (layer) | | <UIImageView: 0x10be34a00; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x10be29480>> | | | <CAGradientLayer: 0x10be26280> (layer) | <UILabel: 0x10be35660; frame = (130 158.8; 60 40); clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x10be357a0>>
これ知るまでは、subviewsを再帰的にロギングしてました。