When a binary is built using PIE, reloading the file will cause GDB to error                                      
on restart.  For example:                                                                                         
gdb ./a.out                                                                                                       
(gdb) break main                                                                                                  
(gdb) run                                                                                                         
(gdb) file ./a.out                                                                                                
(gdb) continue                                                                                                    
                                                                                                                  
Will cause GDB to error with:                                                                                     
Continuing.                                                                                                       
Warning:                                                                                                          
Cannot insert breakpoint 1.                                                                                       
Cannot access memory at address 0x9e0                                                                             
Command aborted.                                                                                                  
                                                                                                                  
This is due to the symbol offsets not being relocated after reloading the file.