[INFO] cloning repository https://github.com/dcrankshaw/rpc-perf-tuning
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dcrankshaw/rpc-perf-tuning" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdcrankshaw%2Frpc-perf-tuning", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdcrankshaw%2Frpc-perf-tuning'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e55de2de36444c70e67ce20ecdbfd528eb22a3d0
[INFO] checking dcrankshaw/rpc-perf-tuning against master#a932eb36f8adf6c8cdfc450f063943da3112d621 for pr-140209-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdcrankshaw%2Frpc-perf-tuning" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] error: failed to write new configuration file /workspace/builds/worker-6-tc1/source/.git/config.lock
[INFO] [stderr] fatal: could not set 'core.logallrefupdates' to 'true'


failed to checkout https://github.com/dcrankshaw/rpc-perf-tuning

Caused by:
    command failed: exit status: 128