> Was the customization done under version control?
Yes it was. My thinking though is that I am getting this error with every probe, not just the ones in xact.c so I suspect there is something more than just a code change to the file. I compared the common makefiles and don't see any changes that would cause the linker error. In any case I'll try to go back through some of the commit history to see if anything stands out. Thanks for the input!