[INFO] cloning repository https://github.com/graeme-winter/mandelbrot-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/graeme-winter/mandelbrot-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgraeme-winter%2Fmandelbrot-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgraeme-winter%2Fmandelbrot-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8709a711fbbcfe121f0a122b41ba047d6a79cda7
[INFO] checking graeme-winter/mandelbrot-rust against master#8f21a5c92ea55c348c275a1bc4fedbdf181e0d64 for pr-143011
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgraeme-winter%2Fmandelbrot-rust" "/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.repositoryformatversion' to '0'


failed to checkout https://github.com/graeme-winter/mandelbrot-rust

Caused by:
    command failed: exit status: 128