When trying to build the server jars, the build fails while applying "Spigot Configuration":
fatal: sha1 information is lacking or useless (src/main/java/net/minecraft/server/World.java).
Repository lacks necessary blobs to fall back on 3-way merge.
Cannot fall back to three-way merge.
Patch failed at 0005 Spigot Configuration

I already tried deleting the whole directory and redownloading the build tools without success. I've tried it on another Windows PC where it also fails at the same point. core.autocrlf was already set to true but I set it again and that didn't work as well.

Building with --rev 1.8 works. When I run the BuildTools after that without the flag in the same directory it also builds Spigot 1.8.3 without problems.