[INFO] cloning repository https://github.com/dais39/hello-rocket
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dais39/hello-rocket" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdais39%2Fhello-rocket", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdais39%2Fhello-rocket'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0a478dc8286c68eeea91465a3f4d1d8809619dba
[INFO] checking dais39/hello-rocket against master#64b185eddaa1d7ddf5e0c024be23b9cbba6c1722 for pr-143929
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdais39%2Fhello-rocket" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-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-0-tc1/source/.git/refs/heads/master.lock'


failed to checkout https://github.com/dais39/hello-rocket

Caused by:
    command failed: exit status: 128