[INFO] cloning repository https://github.com/zhenhuanlee/rust_learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zhenhuanlee/rust_learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzhenhuanlee%2Frust_learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzhenhuanlee%2Frust_learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f0260ca00cf2a85b25360659997043da257c353b
[INFO] checking zhenhuanlee/rust_learn against master#a932eb36f8adf6c8cdfc450f063943da3112d621 for pr-140209-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzhenhuanlee%2Frust_learn" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-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-6-tc1/source/.git/logs/refs/heads/master': No such file or directory


failed to checkout https://github.com/zhenhuanlee/rust_learn

Caused by:
    command failed: exit status: 128