fG!
I can reproduce it. There is something broken with newer lldb version that is triggering this because older versions work fine. Investigating!
Didn't read my own comments because it's already documented in the code. There is some regression where it generates this error when setting a new callback inside another callback. It...
You will need to remove the alias or replace with something else so you can use the original alias if you really want the 'b' shortcut. Otherwise you can use...