+ # So what we're doing below with uniq -u is that we take
+ # lines that have not been duplicated. This computes the
+ # symmetric difference between the files. This is not
+ # what we want. If a file is in the excludes but not in
+ # the sources, we want that file not to show up. By duplicating the
+ # excludes, we ensure that we won't end up in this failure state.