[INFO] cloning repository https://github.com/davidbarsky/tower-client
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/davidbarsky/tower-client" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdavidbarsky%2Ftower-client", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdavidbarsky%2Ftower-client'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 308b2870c1cc99725ab2c7165f24a8564eb642b1
[INFO] testing davidbarsky/tower-client against master#b03b3a7ec92682be2917540b679478d41c95a30c for pr-137122-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdavidbarsky%2Ftower-client" "/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/davidbarsky/tower-client

Caused by:
    command failed: exit status: 128