Why does the debugger 'po' works with 'var' vs 'let'? - swift

Question

Why does the debugger 'po' works with var:
var myDict = currentImageDownloader.dict
As shown here:
(lldb) po myDict
Some
{
[0] = {
key = "ispublic"
value = (instance_type = Builtin.RawPointer = 0xb000000000000013)
(lldb) po myDict
error: <EXPR>:1:1: error: use of unresolved identifier 'myDict'
myDict
...
yet via 'let':
let myDict = currentImageDownloader.dict
The debugger 'po' doesn't work:
(lldb) po myDict
error: <EXPR>:1:1: error: use of unresolved identifier 'myDict'
myDict
^
Although I can view everything via 'let' or 'var' using the debugger's frame command:
(lldb) fr v
(UICollectionView) collectionView = 0x00007fc2d2821600 {
UIKit.UIScrollView = {
UIKit.UIView = {
UIKit.UIResponder = {
ObjectiveC.NSObject = {}
}
}
}
}
(NSIndexPath) indexPath = 0xc000000000000016 {
ObjectiveC.NSObject = {}
}
(FlickrSwift.ViewController) self = 0x00007fc2d2580f20 {
UIKit.UIViewController = {
UIKit.UIResponder = {
ObjectiveC.NSObject = {}
}
}
collectionView = Some
}
(FlickrSwift.ImageDownloader) currentImageDownloader = 0x00007fc2d4449750 {
image = nil
bigImage = nil
dict = Some {
[0] = {
key = "ispublic"
value = (instance_type = Builtin.RawPointer = 0xb000000000000013)
}
[1] = {
key = "height_sq"
value = (instance_type = Builtin.RawPointer = 0xb0000000000004b3)
}
[2] = {
key = "url_m"
value = (instance_type = Builtin.RawPointer = 0x00007fc2d25131a0 -> 0x00000001088e7488 (void *)0x00000001088e7438: __NSCFString)
}
[3] = {
key = "title"
value = (instance_type = Builtin.RawPointer = 0x00007fc2d25a7030 -> 0x00000001088e7488 (void *)0x00000001088e7438: __NSCFString)
}
[4] = {
key = "isfamily"
value = (instance_type = Builtin.RawPointer = 0xb000000000000003)
}
...
}
descString = nil
}
(AnyObject) cell = <variable not available>
(UIImageView) photoImageView = <variable not available>
(UIImage) image = <variable not available>

Answer 1

There were a couple of bugs in the debug information for "let" variables that kept lldb from being able to understand them correctly. These should all be fixed in the upcoming Xcode release. You'll need to recompile your code once you get the new release, but after that you should be able to see them.
If you aren't please file a bug with http://bugreporter.apple.com.