XCode and Subversion - 155005 Error

I was receiving the following error while trying to perform various SCM functions through the Xcode UI:

Error: 155005 (Working copy not locked; this is probably a bug, please report) Description: Directory 'XYZ/.svn' containing working copy admin area is missing

It turns out that I had added my build directory to my repository when I originally added my project. I removed the directory from the repository, removed my working copy, and then checked it out again. Problem solved.