I would love to, but I'm not sure I can.  I need to match an identifier before the equals, (almost always `prefix`, but I like to be general), quotes optionally around the right hand side, and a string after the cellar/prefix.  I suppose I could write a function to emit the regex with the old/new cellars embedded in it and just use the function instead of the regex literal, but I don't think that would save that much in terms of readability.