Ah that xattr error is an issue with the installer attempting to remove an attribute that doesn’t exist, I’ll submit a patch to cmdstan for that later today.
For the warnings during model compilation, this is just saying that one of the functions used by the Boost c++ library (one of our dependencies) has been marked as deprecated. This is completely safe to ignore, and you can suppress this warning in future output by running:
cmdstanr::make_local(cpp_options = list("CXXFLAGS += -Wno-deprecated-declarations"), append = TRUE)