0 libswiftCore.dylib swift_slowAlloc.cold.1 + 16 1 libswiftCore.dylib swift_slowAlloc + 208 2 libswiftCore.dylib swift_allocObject + 52 3 libswiftCore.dylib static _DictionaryStorage.copy(original:) + 144 arrow_right 4 <compiler-generated> - Line 4311977528 specialized _NativeDictionary.copy() + 4311977528 5 <compiler-generated> - Line 4311980408 specialized _NativeDictionary.mutatingFind(_:isUnique:) + 4311980408 6 <compiler-generated> - Line 4311980920 specialized _NativeDictionary.subscript.modify + 4311980920 7 <compiler-generated> - Line 4311980676 specialized Dictionary._Variant.subscript.modify + 4311980676 8 <compiler-generated> - Line 4311976216 Another case 0 libswiftCore.dylib swift_slowAlloc.cold.1 + 16 1 libswiftCore.dylib swift_slowAlloc + 212 2 libswiftCore.dylib swift_allocObject + 64 3 libswiftCore.dylib static _DictionaryStorage.allocate(scale:age:seed:) + 216 4 libswiftCore.dylib Dictionary.init(minimumCapacity:) + 76 It seems that  swift_coldAlloc invoke malloc to allocate memory, but malloc return an invalid pointer, I'm so confused why it happened on iOS 14 only(from FireBase)