[INFO] updating cached repository efyang/conway-piston
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/efyang/conway-piston
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/efyang/conway-piston" "work/ex/pr-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/gh/efyang/conway-piston"`
[INFO] [stderr] Cloning into 'work/ex/pr-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/gh/efyang/conway-piston'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/efyang/conway-piston" "work/ex/pr-57501/sources/try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f/gh/efyang/conway-piston"`
[INFO] [stderr] Cloning into 'work/ex/pr-57501/sources/try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f/gh/efyang/conway-piston'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 17714e7a8c2065554a20713ce6150807c6294947
[INFO] sha for GitHub repo efyang/conway-piston: 17714e7a8c2065554a20713ce6150807c6294947
[INFO] validating manifest of efyang/conway-piston on toolchain master#6ecad338381cc3b8d56e2df22e5971a598eddd6c
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+6ecad338381cc3b8d56e2df22e5971a598eddd6c-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of efyang/conway-piston on toolchain try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f789154f114767b2d0cb9c5b6c592cb3a635e6f-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing efyang/conway-piston
[INFO] finished frobbing efyang/conway-piston
[INFO] frobbed toml for efyang/conway-piston written to work/ex/pr-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/gh/efyang/conway-piston/Cargo.toml
[INFO] started frobbing efyang/conway-piston
[INFO] finished frobbing efyang/conway-piston
[INFO] frobbed toml for efyang/conway-piston written to work/ex/pr-57501/sources/try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f/gh/efyang/conway-piston/Cargo.toml
[INFO] crate efyang/conway-piston has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+6ecad338381cc3b8d56e2df22e5971a598eddd6c-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/pr-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/gh/efyang/conway-piston/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" "+6ecad338381cc3b8d56e2df22e5971a598eddd6c-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed