When I open the project in XCode which was modified yesterday,it shows "scanning for working copies" on the toolbar in the status area.
The project still works, and I can also do the other modification.But the status "scanning for working copies" is always on.I'd like to know what's it for and will it make any influence, and how to do with it.
The "scanning for working copies" seems to mean xcode is looking for a version of your project or one of its files in the version control repository. It may be unable to find it because of a linking error or the files may be corrupt.
The most reliable fix should you encounter the problem again is to remove and re-import your project. Removing your version control repository if you dont need under the Window -> Organiser menu should prevent further issues.
I hope this helps. This is a very frustrating problem, especially when it causes xcode to become unresponsive.