[INFO] updating cached repository bon-chi/tower_of_hanoi_in_rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/bon-chi/tower_of_hanoi_in_rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/bon-chi/tower_of_hanoi_in_rust" "work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/bon-chi/tower_of_hanoi_in_rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/bon-chi/tower_of_hanoi_in_rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/bon-chi/tower_of_hanoi_in_rust" "work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/bon-chi/tower_of_hanoi_in_rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/bon-chi/tower_of_hanoi_in_rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 6db73d2b8c4a3dffb5c55025cbf3bd44d5188ab2
[INFO] sha for GitHub repo bon-chi/tower_of_hanoi_in_rust: 6db73d2b8c4a3dffb5c55025cbf3bd44d5188ab2
[INFO] validating manifest of bon-chi/tower_of_hanoi_in_rust on toolchain master#39401465da4ce27aeeb2c2a26133ac35c63aa515
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of bon-chi/tower_of_hanoi_in_rust on toolchain try#f45cc3094ee337acd688771b9234318046b0572d
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing bon-chi/tower_of_hanoi_in_rust
[INFO] finished frobbing bon-chi/tower_of_hanoi_in_rust
[INFO] frobbed toml for bon-chi/tower_of_hanoi_in_rust written to work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/bon-chi/tower_of_hanoi_in_rust/Cargo.toml
[INFO] started frobbing bon-chi/tower_of_hanoi_in_rust
[INFO] finished frobbing bon-chi/tower_of_hanoi_in_rust
[INFO] frobbed toml for bon-chi/tower_of_hanoi_in_rust written to work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/bon-chi/tower_of_hanoi_in_rust/Cargo.toml
[INFO] crate bon-chi/tower_of_hanoi_in_rust already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking bon-chi/tower_of_hanoi_in_rust against master#39401465da4ce27aeeb2c2a26133ac35c63aa515 for pr-60914
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-60914/worker-2/master#39401465da4ce27aeeb2c2a26133ac35c63aa515:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/bon-chi/tower_of_hanoi_in_rust:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 6cdad8c26b97725780f52033870c05568dc65b01d0313d2bfe6eda8afcae84e9
[INFO] running `"docker" "start" "-a" "6cdad8c26b97725780f52033870c05568dc65b01d0313d2bfe6eda8afcae84e9"`
[INFO] [stderr]     Checking tower_of_hanoi_in_rust v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:22:9
[INFO] [stderr]    |
[INFO] [stderr] 22 |     let mut new_stream: &mut Vec<i32> = &mut hanoi_stream(n - 1, h1);
[INFO] [stderr]    |         ----^^^^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:22:9
[INFO] [stderr]    |
[INFO] [stderr] 22 |     let mut new_stream: &mut Vec<i32> = &mut hanoi_stream(n - 1, h1);
[INFO] [stderr]    |         ----^^^^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.44s
[INFO] running `"docker" "inspect" "6cdad8c26b97725780f52033870c05568dc65b01d0313d2bfe6eda8afcae84e9"`
[INFO] running `"docker" "rm" "-f" "6cdad8c26b97725780f52033870c05568dc65b01d0313d2bfe6eda8afcae84e9"`
[INFO] [stdout] 6cdad8c26b97725780f52033870c05568dc65b01d0313d2bfe6eda8afcae84e9