I'm using Mixtral 8x7b as a llamafile on an M1 regularly for coding help and general Q&A. It's really something wonderful to just run a single command and have this incredible offline resource.
In my case I got the runtime detection issue (explained in the README "gotcha" section). Solved my running "assimilate" [3] on the downloaded llamafile.
[1] https://github.com/Mozilla-Ocho/llamafile/
[2] https://huggingface.co/jartine/Mixtral-8x7B-Instruct-v0.1-llamafile/resolve/main/mixtral-8x7b-instruct-v0.1.Q5_K_M.llamafile?download=true
[3] https://cosmo.zip/pub/cosmos/bin/assimilate