[INFO] cloning repository BurntSushi/rust-docs
[INFO] running `"git" "clone" "--bare" "git://github.com/BurntSushi/rust-docs.git" "work/cache/sources/gh/BurntSushi/rust-docs"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/BurntSushi/rust-docs'...
[INFO] running `"git" "clone" "work/cache/sources/gh/BurntSushi/rust-docs" "work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/BurntSushi/rust-docs"`
[INFO] [stderr] Cloning into 'work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/BurntSushi/rust-docs'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/BurntSushi/rust-docs" "work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/gh/BurntSushi/rust-docs"`
[INFO] [stderr] Cloning into 'work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/gh/BurntSushi/rust-docs'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 28852fea71fc24a0d53cc2573b255bf677597ac8
[INFO] sha for GitHub repo BurntSushi/rust-docs: 28852fea71fc24a0d53cc2573b255bf677597ac8
[INFO] validating manifest of BurntSushi/rust-docs on toolchain master#c0086b9e8972fef9fd4af24bae20d45021ed06c6
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of BurntSushi/rust-docs on toolchain try#290ac7b29f41ff9fa5232f9a1116ea71a3501063
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+290ac7b29f41ff9fa5232f9a1116ea71a3501063-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing BurntSushi/rust-docs
[INFO] finished frobbing BurntSushi/rust-docs
[INFO] frobbed toml for BurntSushi/rust-docs written to work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/BurntSushi/rust-docs/Cargo.toml
[INFO] started frobbing BurntSushi/rust-docs
[INFO] finished frobbing BurntSushi/rust-docs
[INFO] frobbed toml for BurntSushi/rust-docs written to work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/gh/BurntSushi/rust-docs/Cargo.toml
[INFO] crate BurntSushi/rust-docs has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on the registry index
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/BurntSushi/rust-docs/Cargo.lock needs to be updated but --locked was passed to prevent this
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c0086b9e8972fef9fd4af24bae20d45021ed06c6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed