[INFO] cloning repository https://github.com/npnguyen99/Regex
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/npnguyen99/Regex" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnpnguyen99%2FRegex", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnpnguyen99%2FRegex'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3de650f43493bc03bef2a36ca8adc3cd9a52f05e
[INFO] checking npnguyen99/Regex against master#9f48dedc9763334a587c66558974635807a113ed for pr-137394
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnpnguyen99%2FRegex" "/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 ref 'refs/heads/master': couldn't write '/workspace/builds/worker-5-tc1/source/.git/refs/heads/master.lock'


failed to checkout https://github.com/npnguyen99/Regex

Caused by:
    command failed: exit status: 128