How else do you answer questions like "How long has this been broken?" And without the answer to that, how do you know who needs to upgrade, and who doesn't? I

How else do you answer questions like "How long has this been broken?" And without the answer to that, how do you know who needs to upgrade, and who doesn't? I'm sure you can install old binaries to answer this sometimes, but I'd prefer to do it with a DVCS bisect, since that'll narrow the matter down to the individual commit that broke things.