[INFO] updating cached repository dat2/futures-example
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/dat2/futures-example
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/dat2/futures-example" "work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/dat2/futures-example"`
[INFO] [stderr] Cloning into 'work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/dat2/futures-example'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/dat2/futures-example" "work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/dat2/futures-example"`
[INFO] [stderr] Cloning into 'work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/dat2/futures-example'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 82adcae20bab8f4760dcfa0e6de615aa3d0012b7
[INFO] sha for GitHub repo dat2/futures-example: 82adcae20bab8f4760dcfa0e6de615aa3d0012b7
[INFO] validating manifest of dat2/futures-example on toolchain master#e2f221c75932de7a29845c8d6f1f73536ad00c41
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e2f221c75932de7a29845c8d6f1f73536ad00c41-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of dat2/futures-example on toolchain try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0bfb90d213a93e466b33d078a5b535a2a6f9c5ff-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing dat2/futures-example
[INFO] finished frobbing dat2/futures-example
[INFO] frobbed toml for dat2/futures-example written to work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/dat2/futures-example/Cargo.toml
[INFO] started frobbing dat2/futures-example
[INFO] finished frobbing dat2/futures-example
[INFO] frobbed toml for dat2/futures-example written to work/ex/pr-57617/sources/try#0bfb90d213a93e466b33d078a5b535a2a6f9c5ff/gh/dat2/futures-example/Cargo.toml
[INFO] crate dat2/futures-example has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e2f221c75932de7a29845c8d6f1f73536ad00c41-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/pr-57617/sources/master#e2f221c75932de7a29845c8d6f1f73536ad00c41/gh/dat2/futures-example/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" "+e2f221c75932de7a29845c8d6f1f73536ad00c41-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed