See issue #3944. Currently (f5) FSFS packs revprops into SQLite. We want to redesign that (calling the new design f6), but we don't have time for that before releasing 1.7.0. As an interim solution, this issue calls for removing f5 from trunk, releasing 1.7 with f4 (the same as in 1.6). Looking forward, issue #3944 calls for of designing and releasing f6 in 1.8. Format 5 will remain unsupported into the future; repositories that use it (created by 1.7-dev) will have to be dump/loaded using trunk/1.7.0-alpha3 code. A tools/ scripts to upgrade/downgrade f5 into f4 or f6 may be written in the future.