Can someone with engine knowledge look at this attempt to run the rust tests on macos on Github Actions: https://github.com/pantsbuild/pants/runs/1966138049?check_suite_focus=true

thread 'syscall_tests::read_file_by_digest_exact_bytes' panicked at 'Bad fd -1', fs/brfs/src/syscall_tests.rs:39:5

is brfs even used?