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:
864f1124 SPIGOT-6017: BoundingBox#rayTrace returns incorrect null
Spigot Changes:
9639cf78 SPIGOT-6027: CraftMetaBook clone uses old BookMeta.Spigot
a9e08ce8c6