[INFO] cloning repository https://github.com/swissfranks/rust-guessing-game
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/swissfranks/rust-guessing-game" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswissfranks%2Frust-guessing-game", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswissfranks%2Frust-guessing-game'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4860b960cdcd25946be36b052adb8772cdf08791
[INFO] checking swissfranks/rust-guessing-game against master#d2eadb7a94ef8c9deb5137695df33cd1fc5aee92 for pr-137268
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswissfranks%2Frust-guessing-game" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-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-3-tc1/source/.git/refs/heads/master.lock'


failed to checkout https://github.com/swissfranks/rust-guessing-game

Caused by:
    command failed: exit status: 128