I see your intent now.  The instructions tell you to compare against "the most recent release found on `Launchpad <https://launchpad.net/juju-gui/trunk>`".  That's the trunk series, so it should *only* have the juju-gui-LASTVERSION+build.HASH.xz files.  There won't be a "bigger" there by your definition.  The LASTVERSION might or might not have increased, and the HASH is unordered.

I think we can just remove this line.