Robolectric doesn't like spaces in the user profile path

Today I helped someone who was trying to run Robolectric tests but found that they crashed with a FileNotFoundException for a JAR somewhere under their user profile directory. This user's profile folder had a space in the name that the error message displayed as %20. Apparently the path was getting URL-encoded somewhere along the way. We worked around the problem by creating a symbolic link (mklink /d) in C:\Users from the mangled name to the actual user profile folder.