[INFO] cloning repository MercuryProject/mercury
[INFO] running `"git" "clone" "--bare" "git://github.com/MercuryProject/mercury.git" "work/cache/sources/gh/MercuryProject/mercury"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/MercuryProject/mercury'...
[INFO] running `"git" "clone" "work/cache/sources/gh/MercuryProject/mercury" "work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/MercuryProject/mercury"`
[INFO] [stderr] Cloning into 'work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/MercuryProject/mercury'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/MercuryProject/mercury" "work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/gh/MercuryProject/mercury"`
[INFO] [stderr] Cloning into 'work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/gh/MercuryProject/mercury'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] c888682b76c2b9c16c00b5c9f43d411f8f47a3ad
[INFO] sha for GitHub repo MercuryProject/mercury: c888682b76c2b9c16c00b5c9f43d411f8f47a3ad
[INFO] validating manifest of MercuryProject/mercury 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 MercuryProject/mercury 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 MercuryProject/mercury
[INFO] finished frobbing MercuryProject/mercury
[INFO] frobbed toml for MercuryProject/mercury written to work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/MercuryProject/mercury/Cargo.toml
[INFO] started frobbing MercuryProject/mercury
[INFO] finished frobbing MercuryProject/mercury
[INFO] frobbed toml for MercuryProject/mercury written to work/ex/pr-58899/sources/try#290ac7b29f41ff9fa5232f9a1116ea71a3501063/gh/MercuryProject/mercury/Cargo.toml
[INFO] crate MercuryProject/mercury 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] error: the lock file /mnt/big/crater/work/ex/pr-58899/sources/master#c0086b9e8972fef9fd4af24bae20d45021ed06c6/gh/MercuryProject/mercury/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