[INFO] cloning repository https://github.com/dummyheaad/binary-exponentiation
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dummyheaad/binary-exponentiation" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdummyheaad%2Fbinary-exponentiation", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdummyheaad%2Fbinary-exponentiation'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 98bd8c6275ad21b5ec96e04bbc48953087e9745c
[INFO] checking dummyheaad/binary-exponentiation against master#d93f678fa55842cccd2f091deccd93e9494b3764 for pr-138844
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdummyheaad%2Fbinary-exponentiation" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] [stderr] error: Unable to create '/workspace/builds/worker-7-tc1/source/.git/refs/remotes/origin/HEAD.lock': No such file or directory
[INFO] [stderr] fatal: unable to update refs/remotes/origin/HEAD


failed to checkout https://github.com/dummyheaad/binary-exponentiation

Caused by:
    command failed: exit status: 128