[INFO] cloning repository https://github.com/pacman82/mandelbrot
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/pacman82/mandelbrot" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpacman82%2Fmandelbrot", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpacman82%2Fmandelbrot'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 246c9ea9d931839008092afd9bb55f2f5dbaef8d
[INFO] checking pacman82/mandelbrot against master#613bdd49978298648ed05ace086bd1ecad54b44a for pr-136458
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpacman82%2Fmandelbrot" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] error: failed to write new configuration file /workspace/builds/worker-4-tc1/source/.git/config.lock
[INFO] [stderr] fatal: could not set 'core.filemode' to 'true'


failed to checkout https://github.com/pacman82/mandelbrot

Caused by:
    command failed: exit status: 128