gdb: Invalidation

 
 28.5 Invalidation Notices
 =========================
 
 The following annotations say that certain pieces of state may have
 changed.
 
 '^Z^Zframes-invalid'
 
      The frames (for example, output from the 'backtrace' command) may
      have changed.
 
 '^Z^Zbreakpoints-invalid'
 
      The breakpoints may have changed.  For example, the user just added
      or deleted a breakpoint.