I downloaded the current master f8183e187b in tar.gz format and launched build boot roms t400_8mb but get the following error:
build boot roms t400_8mb
cat: version: No such file or directory
Error: build/roms: something went wrong
It seems to me that the missing file is due to the resources/scripts/misc/versioncheck script which should generate it, but fails because it is assuming the source has been downloaded with git.
I don't know, maybe git is the only supported way to get and build Libreboot and so this behaviour is expected, just wanted to point it out.