[INFO] updating cached repository MercuryProject/mercury
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/MercuryProject/mercury
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/MercuryProject/mercury" "work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/MercuryProject/mercury"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/MercuryProject/mercury'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/MercuryProject/mercury" "work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/MercuryProject/mercury"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/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#f66e4697ae286985ddefc53c3a047614568458bb
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of MercuryProject/mercury on toolchain try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-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-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/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-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/MercuryProject/mercury/Cargo.toml
[INFO] crate MercuryProject/mercury has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/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" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed