Merging this will change how fedpkg writes the sources files, in a way that will break older versions of pyrpkg-based tools.

That means once we merge this and push an updated package to Fedora/EPEL, everybody must upgrade.

Being so disruptive, this change should be bundled with the other planned breaking changes in fedpkg

Could you please sign-off on your commit? (git commit -s). (And ideally also rebase on master.)

The plan is to do a flag day and switch the lookaside checksum on December 12th, so this should be merged now.

@lsedlar done.