[INFO] cloning repository https://github.com/cs3238-tsuzu/umaximize
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cs3238-tsuzu/umaximize" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcs3238-tsuzu%2Fumaximize", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcs3238-tsuzu%2Fumaximize'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ba7b06c17e95c5f234b1baeb7b940e71ff0edf18
[INFO] checking cs3238-tsuzu/umaximize against master#fd17deacce374a4185c882795be162e17b557050 for pr-138001
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcs3238-tsuzu%2Fumaximize" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] error: failed to write new configuration file /workspace/builds/worker-0-tc1/source/.git/config.lock
[INFO] [stderr] fatal: could not set 'core.repositoryformatversion' to '0'


failed to checkout https://github.com/cs3238-tsuzu/umaximize

Caused by:
    command failed: exit status: 128