[llvm-bugs] [Bug 31308] New: po sometimes prints blank instead of object

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=31308

            Bug ID: 31308
           Summary: po sometimes prints blank instead of object
           Product: lldb
           Version: 3.6
          Hardware: Macintosh
                OS: MacOS X
            Status: NEW
          Severity: normal
          Priority: P
         Component: All Bugs
          Assignee: lldb-dev at lists.llvm.org
          Reporter: mth at xmission.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

My debug environment is Xcode 8.1 stopped at a breakpoint while debugging an
iOS application (usually 9.3.5 or 10.1) written in Objective C.  Sometimes when
I use po to print an object, all it prints is a blank line. Printing with
different syntax will sometimes make it work.  In this particular example the
object was a property of the argument to a simple method:

- (void)handleDataModelChange: (NSNotification *)nt
{
    NSSet *updatedObjects = [[nt userInfo] objectForKey: NSUpdatedObjectsKey];
    ...
}

The breakpoint was set near the end of the method.  Here is the output of some
po commands I tried.  The last po command prints the object as it should be
printed by the first two po commands.  Instead they just give blank lines.

(lldb) po nt.object

(lldb) po [nt object]

(lldb) po [nt.object class]
NSManagedObjectContext

(lldb) po (NSManagedObject *)nt.object
<NSManagedObjectContext: 0x14576d20>: defaultMainQueueContext



[lldb --version prints lldb-360.1.65]

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