Weird behaviour of Xcode 11 Debugger - Showing values as nil when there's a value

Question

I just noticed weird behaviour of Xcode11, I am executing same code in Xcode 10 and Xcode 11.

See the below attached screenshot for both the versions.

I am c

Answer 1

I am using an answer since for the comment would be too long, but would be more appropriate.

I am currently (catalina, xcode 11.1) facing many similar issues, beside a general slow down of the debugger.

To be sure anyway:

• check that in the target build settings the compile time optimization is disabled for debug: Optimization Level -O0 (the var may be optimized away)
• this solved some of my issues as well (disabling the diagnostic made lldb a bit faster and solved issues with p/po and collecting the stacktrace): Xcode 11 extremely slow - A known problem?

Answer 2

This is a known bug, affecting LLDB (the Xcode debugger) as well as the REPL. It's purely a matter of display:

https://bugs.swift.org/plugins/servlet/mobile#issue/SR-11593

https://bugs.swift.org/plugins/servlet/mobile#issue/SR-11546

And see:

Instantiated optional variable shows as nil in Xcode debugger

An easy workaround for now is to pass thru the bridged Objective C type. The bug is only with the Swift Foundation overlay type. So in this case just cast to NSURL.

So for example:

But: