I have an Xcode project which includes a sub project. After upgrading to Xcode 7 breakpoints in the sub project are not hit nor can I step into functions calls of the sub project. Some breakpoints do get hit but they just show assembly for the call so it seems the sub-project is not being symbolicated correctly. I've checked all the usual sort of things i.e. is generating debug symbols, build configuration on debug is not release and things of this nature shown in Xcode project settings. Anything else I might be missing? In Xcode 6.4 this was not an issue.
This was an issue with not having the correct debug information format set in the hosting project. I resolved by creating a dummy/test Xcode project and comparing the debug file format detailed for each configuration to that in the trouble making project changing the debug information format to match the dummy/test project.