[INFO] cloning repository https://github.com/slightknack/ttfi
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/slightknack/ttfi" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslightknack%2Fttfi", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslightknack%2Fttfi'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8a8a0a82c5d912ce5f6ee82679a7056242567155
[INFO] checking slightknack/ttfi against master#75530e9f72a1990ed2305e16fd51d02f47048f12 for pr-135899
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslightknack%2Fttfi" "/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.filemode' to 'true'


failed to checkout https://github.com/slightknack/ttfi

Caused by:
    command failed: exit status: 128