To be able to change a breakpoint to any file that is under version control, select Allow the source code to be different from the original
version. By default, if you set a breakpoint to a file that is under source control, the breakpoint
is hit only if the working copy of the file exactly matches the version that the executable was compiled from. The breakpoint is not hit if you have modified the working copy of the file.
Selecting this option enables you to change breakpoints to files that are under version control, even if they have been modified.