[INFO] updating cached repository prewk/img_diff
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/prewk/img_diff
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/prewk/img_diff" "work/ex/pr-57745/sources/master#f613dc138b4012cf3d2eb40718fbcc7cf0a34039/gh/prewk/img_diff"`
[INFO] [stderr] Cloning into 'work/ex/pr-57745/sources/master#f613dc138b4012cf3d2eb40718fbcc7cf0a34039/gh/prewk/img_diff'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/prewk/img_diff" "work/ex/pr-57745/sources/try#29640c57b5f92febba0e40c50cb863c9a7ede51d/gh/prewk/img_diff"`
[INFO] [stderr] Cloning into 'work/ex/pr-57745/sources/try#29640c57b5f92febba0e40c50cb863c9a7ede51d/gh/prewk/img_diff'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a97fe31a8d313dca2961a9a1d48496d6248262db
[INFO] sha for GitHub repo prewk/img_diff: a97fe31a8d313dca2961a9a1d48496d6248262db
[INFO] validating manifest of prewk/img_diff on toolchain master#f613dc138b4012cf3d2eb40718fbcc7cf0a34039
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f613dc138b4012cf3d2eb40718fbcc7cf0a34039-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of prewk/img_diff on toolchain try#29640c57b5f92febba0e40c50cb863c9a7ede51d
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+29640c57b5f92febba0e40c50cb863c9a7ede51d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing prewk/img_diff
[INFO] finished frobbing prewk/img_diff
[INFO] frobbed toml for prewk/img_diff written to work/ex/pr-57745/sources/master#f613dc138b4012cf3d2eb40718fbcc7cf0a34039/gh/prewk/img_diff/Cargo.toml
[INFO] started frobbing prewk/img_diff
[INFO] finished frobbing prewk/img_diff
[INFO] frobbed toml for prewk/img_diff written to work/ex/pr-57745/sources/try#29640c57b5f92febba0e40c50cb863c9a7ede51d/gh/prewk/img_diff/Cargo.toml
[INFO] crate prewk/img_diff has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f613dc138b4012cf3d2eb40718fbcc7cf0a34039-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/pr-57745/sources/master#f613dc138b4012cf3d2eb40718fbcc7cf0a34039/gh/prewk/img_diff/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" "+f613dc138b4012cf3d2eb40718fbcc7cf0a34039-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed