[INFO] updating cached repository https://github.com/rust-lang-nursery/chalk
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] [stderr] From https://github.com/rust-lang-nursery/chalk
[INFO] [stderr]  + 0b2bd31b...b510bbc1 gh-pages   -> gh-pages  (forced update)
[INFO] [stderr]    f85bb2ed..2939913f  master     -> master
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 2939913fb7bb94ac2a6721087dc086be11410702
[ERROR] this task or one of its parent failed!
[ERROR] command `"/workspace/cargo-home/bin/cargo" "+b1f395de642e8be7bcbbd2bd8aaadab715851f49" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.