[INFO] cloning repository https://github.com/slymon99/raytracer
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/slymon99/raytracer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslymon99%2Fraytracer", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslymon99%2Fraytracer'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f5d05b84c72b77aa60d970ffb97afd2073a94056
[INFO] checking slymon99/raytracer against master#2a023bf80a6fbd6a06d5460a34eb247b986286ed for pr-143764
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslymon99%2Fraytracer" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-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-7-tc1/source/.git/refs/heads/master.lock'


failed to checkout https://github.com/slymon99/raytracer

Caused by:
    command failed: exit status: 128