Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
79f6ba25 Skip tests on default builds
b85cc32f Further discourage World.regenerateChunk
CraftBukkit Changes:
7560d3b5 Skip tests on default builds
d0a9130d SPIGOT-4563: Fix regenerating chunks saved to disk already
Spigot Changes:
8173d06f Remove need for redundant second clone of repositories
8ede0393 Rebuild patches
Portion of diff was dropped in the mappings update commit.
Also remove the option to remove invalid statistics. The server will
automatically do this now as of... 1.13?, our option wasn't even doing anything.