po Swift String "unresolved identifier"

Question

I am having trouble debugging Swift Strings

func stringTest() {

    let test1:String =   "test1";
    let test2:NSString = "test2";

    // <-- Breakpoint here

    println(test1);
    println(test2);
}

If I set a breakpoint after these lines and try and print test1 I get the following error:

po test1
error: <REPL>:1:1: error: use of unresolved identifier 'test1'
test1
^

But I am able to print test2 successfully:

po test2
test2

Have you tried printing them directly in your code, not from the debugger? This should work. — Undo, Jun 19 '14 at 14:28
Beta software. Debug console for swift is useless at the moment. — Kreiri, Jun 19 '14 at 14:34
Yes, I am able to print both directly from code, it is just using the debugger that I get the error. — Errortype520, Jun 19 '14 at 14:34
(Maybe it's the semicolons? Seriously; that's the only difference between your code and mine, that works...) — Matt Gibson, Jun 19 '14 at 14:50

score 17 · Answer 1 · edited Jan 19 '15 at 01:53

17

It is a bug of Beta. Xcode6-Beta5 has still this bug. You can only get debug info for swift's variables, but can't get it for swift's constants. Temporarily you can change let test1 to var test1 and you will got debug info. Hope this will be fixed in release version. Good Luck in debugging ;)

EDIT: Unfortunately, the same issue is still happening in first release of Xcode Version 6.0.1 (6A317)

let test1:String  -> debug info is unavailable
var test1:String  -> debug info is available

EDIT2: Yes, confirmed. It is fixed also for iOS apps in the latest Xcode 6.1 under OS X Yosemite.

edited Jan 19 '15 at 01:53

xuzhe

5,100
22
28

answered Aug 23 '14 at 20:41

slamor

3,355
2
14
13

Seems to be fixed in Xcode 6.1 (6A1042b); at least in OS X apps, possibly still a bug with iOS apps. – Mike S Oct 04 '14 at 04:55
Xcode 6.1 fixes it for iOS apps as well. (My question about it [here](http://stackoverflow.com/questions/26189424/how-to-view-value-of-swift-let-constant-in-xcode-6-debugger) came from an iOS app.) – George WS Oct 11 '14 at 05:07
Broken again in 6.3 Beta 1, fixed again in 6.3 Beta 2 – Chris Conover Mar 11 '15 at 01:34
1

Xcode 6.3.2 still has such issues from time to time. – Wingzero Jun 15 '15 at 03:39
Xcode 6.4 also. Mostly on class-vars. Any of: 'p self.myVar', 'p myVar', 'po myVar'... all fail – bauerMusic Jul 21 '15 at 07:35
2

2 Months later, still an issue in Xcode 8.2.1. Its embarassing. – Zeeshan Jan 15 '17 at 15:51

score 8 · Accepted Answer · answered Jun 20 '14 at 20:15

8

This is most likely a bug in the debug information output. You can check this by grabbing the PC, for instance from register read pc, and then doing:

(lldb) image lookup -va <PC VALUE>

That will print a bunch of stuff, but the last entries will be all the variables currently visible to the debugger, and where they live (in registers or memory.) If you don't see the variable there, then the debug information must have told lldb that the variable is not currently live.

If you can reproduce this in some example code you can make available, please file a bug with bug reporter.apple.com.

answered Jun 20 '14 at 20:15

Jim Ingham

25,260
2
55
63

I tried your image lookup instruction and I can see my variables : Variable: id = {0x1600000179}, name = "visibleRect", type = "CoreGraphics.CGRect", location = DW_OP_piece(0x8) DW_OP_constu(0x0) v9 DW_OP_piece(0x8) v10 DW_OP_piece(0x8), decl = QuestionListLayoutHandler.swift:22 even though the po doesn't work : error: :2:1: error: use of unresolved identifier 'visibleRect' Any idea why ? (XCode 8.2) I have this nearly on all my code since a few days. – CedricSoubrie Dec 23 '16 at 10:00

po Swift String "unresolved identifier"

2 Answers2

Linked