[INFO] cloning repository https://github.com/ziyi-yan/rust_os
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ziyi-yan/rust_os" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fziyi-yan%2Frust_os", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fziyi-yan%2Frust_os'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 441c1c402faa69546e03e126c4f8813da3c3109f
[INFO] checking ziyi-yan/rust_os against master#667247db71ea18c4130dd018d060e7f09d589490 for pr-140824
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fziyi-yan%2Frust_os" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] [stderr] fatal: update_ref failed for ref 'HEAD': cannot update the ref 'refs/heads/master': unable to create directory for '/workspace/builds/worker-5-tc1/source/.git/logs/refs/heads/master': No such file or directory


failed to checkout https://github.com/ziyi-yan/rust_os

Caused by:
    command failed: exit status: 128