Can you add verbose or trace flags? Your error is too short. “BUG” and “Error” doesn’t tell us what broke in ffi or why.
Also, few people here will know how to debug the new command.
Try making a project with index.md file and run
jekyll serve --trace
And see what happens
I am getting the same error.
Have you tried seeing what other M1 users on the forum have done?
Or if you search your exact error on stack overflow or google.