How do I get line numbers instead of linear offsets in symbolic crash reports?

I have a question that has been troubling me for a while. For our symbolized crash reports for internal frameworks for which we have source code, symbolized crash reports often have offsets instead of line numbers. For example, a symbolic report contains:

*AppName*   0x0025b0b2 -[*AppSpecificClass AppSpecificMessage*:] + 682

      

        
        
        
      

    

if we want:

*AppName*   0x001c444d __39-[*AppSpecificClass AppSpecificMessage*] (*AppSpecificClass*.m:145)

      

        
        
        
      

    

I've tried a bunch of different permutations of build settings, but I can't seem to get this to work consistently (we get line numbers for some parts of the crash).

Thanks for the help, Rob