[INFO] cloning repository https://github.com/muyuu/rust-rpn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/muyuu/rust-rpn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmuyuu%2Frust-rpn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmuyuu%2Frust-rpn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5b4b3bedb4ea792efc4200e62f73513c691ec103
[INFO] checking muyuu/rust-rpn against master#cd805f09ffbfa3896c8f50a619de9b67e1d9f3c3 for pr-135841
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmuyuu%2Frust-rpn" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] error: failed to write new configuration file /workspace/builds/worker-2-tc1/source/.git/config.lock
[INFO] [stderr] fatal: could not set 'core.repositoryformatversion' to '0'


failed to checkout https://github.com/muyuu/rust-rpn

Caused by:
    command failed: exit status: 128