I was experimenting with two different versions of the same routine in different libraries. I had a path to each library directory, and would change the order to test one or the other. The two paths were:
The order is specified in Project Properties, C/C++ Build->Settings->Tool Settings->CrossCore Blackfin Linker->General . I found that the Debug directory was always put last on the list no matter where I had it in the Library Search Directories box. It turned out that it needed to have double quotes around it like the other directory entries. Leaving off quotes caused it to always be at the end. Adding the quotes fixed it, but wasn't obvious!