[INFO] crate qemu-rust 0.1.0 is already in cache
[INFO] extracting crate qemu-rust 0.1.0 into work/ex/beta-1.37-6/sources/1.36.0/reg/qemu-rust/0.1.0
[INFO] extracting crate qemu-rust 0.1.0 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/qemu-rust/0.1.0
[INFO] validating manifest of qemu-rust-0.1.0 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of qemu-rust-0.1.0 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing qemu-rust-0.1.0
[INFO] finished frobbing qemu-rust-0.1.0
[INFO] frobbed toml for qemu-rust-0.1.0 written to work/ex/beta-1.37-6/sources/1.36.0/reg/qemu-rust/0.1.0/Cargo.toml
[INFO] started frobbing qemu-rust-0.1.0
[INFO] finished frobbing qemu-rust-0.1.0
[INFO] frobbed toml for qemu-rust-0.1.0 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/qemu-rust/0.1.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache lock
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/qemu-rust/0.1.0/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" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed