[INFO] cloning repository https://github.com/VoxWave/a-b-list-sorter
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/VoxWave/a-b-list-sorter" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVoxWave%2Fa-b-list-sorter", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVoxWave%2Fa-b-list-sorter'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 08a0357a4ee6937f48fd2674f7d1aaac778a56c6
[INFO] testing VoxWave/a-b-list-sorter against beta-2021-09-12 for beta-1.56-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVoxWave%2Fa-b-list-sorter" "/workspace/builds/worker-28/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-28/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/VoxWave/a-b-list-sorter on toolchain beta-2021-09-12
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-12" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/VoxWave/a-b-list-sorter
[INFO] finished tweaking git repo https://github.com/VoxWave/a-b-list-sorter
[INFO] tweaked toml for git repo https://github.com/VoxWave/a-b-list-sorter written to /workspace/builds/worker-28/source/Cargo.toml
[INFO] crate git repo https://github.com/VoxWave/a-b-list-sorter already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-12" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-12" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d55b931a161d6b2d3c8d625b9caf288637b9e312a71c05b4361f4eeeed41530b
[INFO] running `Command { std: "docker" "start" "-a" "d55b931a161d6b2d3c8d625b9caf288637b9e312a71c05b4361f4eeeed41530b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d55b931a161d6b2d3c8d625b9caf288637b9e312a71c05b4361f4eeeed41530b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d55b931a161d6b2d3c8d625b9caf288637b9e312a71c05b4361f4eeeed41530b", kill_on_drop: false }`
[INFO] [stdout] d55b931a161d6b2d3c8d625b9caf288637b9e312a71c05b4361f4eeeed41530b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-12" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] eff366efd2ff7b122664cbe06225aa3460cea68ab083b6eb7297be446a2b5841
[INFO] running `Command { std: "docker" "start" "-a" "eff366efd2ff7b122664cbe06225aa3460cea68ab083b6eb7297be446a2b5841", kill_on_drop: false }`
[INFO] [stderr]    Compiling list_sorter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.21s
[INFO] running `Command { std: "docker" "inspect" "eff366efd2ff7b122664cbe06225aa3460cea68ab083b6eb7297be446a2b5841", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "eff366efd2ff7b122664cbe06225aa3460cea68ab083b6eb7297be446a2b5841", kill_on_drop: false }`
[INFO] [stdout] eff366efd2ff7b122664cbe06225aa3460cea68ab083b6eb7297be446a2b5841
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-12" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 82f9318a4b0d2aa0cf689d2dd67bf2a9d5586956338d034e3b6ffe0a9229eca6
[INFO] running `Command { std: "docker" "start" "-a" "82f9318a4b0d2aa0cf689d2dd67bf2a9d5586956338d034e3b6ffe0a9229eca6", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.68
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling list_sorter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:262:9
[INFO] [stdout]     |
[INFO] [stdout] 262 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 262 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:296:9
[INFO] [stdout]     |
[INFO] [stdout] 296 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 296 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:323:9
[INFO] [stdout]     |
[INFO] [stdout] 323 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 323 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:335:9
[INFO] [stdout]     |
[INFO] [stdout] 335 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 335 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:358:9
[INFO] [stdout]     |
[INFO] [stdout] 358 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 358 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:391:9
[INFO] [stdout]     |
[INFO] [stdout] 391 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 391 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/main.rs:424:9
[INFO] [stdout]     |
[INFO] [stdout] 424 |         &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 424 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1m 00s
[INFO] running `Command { std: "docker" "inspect" "82f9318a4b0d2aa0cf689d2dd67bf2a9d5586956338d034e3b6ffe0a9229eca6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "82f9318a4b0d2aa0cf689d2dd67bf2a9d5586956338d034e3b6ffe0a9229eca6", kill_on_drop: false }`
[INFO] [stdout] 82f9318a4b0d2aa0cf689d2dd67bf2a9d5586956338d034e3b6ffe0a9229eca6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-28/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-12" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 9ae8388fc4c109d188d68967282decec4f55b5ee355ec460da1ab419b20f047b
[INFO] running `Command { std: "docker" "start" "-a" "9ae8388fc4c109d188d68967282decec4f55b5ee355ec460da1ab419b20f047b", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:262:9
[INFO] [stderr]     |
[INFO] [stderr] 262 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 262 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:296:9
[INFO] [stderr]     |
[INFO] [stderr] 296 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 296 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:323:9
[INFO] [stderr]     |
[INFO] [stderr] 323 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 323 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:335:9
[INFO] [stderr]     |
[INFO] [stderr] 335 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 335 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:358:9
[INFO] [stderr]     |
[INFO] [stderr] 358 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 358 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:391:9
[INFO] [stderr]     |
[INFO] [stderr] 391 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 391 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused borrow that must be used
[INFO] [stderr]    --> src/main.rs:424:9
[INFO] [stderr]     |
[INFO] [stderr] 424 |         &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stderr]     |
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 424 |         let _ = &mut sorted.shuffle(&mut rng);
[INFO] [stderr]     |         +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: `list_sorter` (bin "list_sorter" test) generated 7 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.27s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/list_sorter-3940f487ec85ab4f)
[INFO] [stdout] running 11 tests
[INFO] [stdout] test merge_sort_test_1 ... ok
[INFO] [stdout] test merge_sort_test_2 ... ok
[INFO] [stdout] test runs_should_be_the_same ... ok
[INFO] [stdout] test sort_test_1 ... ok
[INFO] [stdout] test sort_test_2 ... ok
[INFO] [stdout] test merge_is_better_than_std ... ok
[INFO] [stdout] test merge_is_better_than_std_unstable ... ok
[INFO] [stdout] test merge_sort_test_3 ... ok
[INFO] [stdout] test sort_test_3 ... ok
[INFO] [stdout] test merge_is_better_2 ... ok
[INFO] [stdout] test merge_is_better ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 11 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 8.91s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "9ae8388fc4c109d188d68967282decec4f55b5ee355ec460da1ab419b20f047b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9ae8388fc4c109d188d68967282decec4f55b5ee355ec460da1ab419b20f047b", kill_on_drop: false }`
[INFO] [stdout] 9ae8388fc4c109d188d68967282decec4f55b5ee355ec460da1ab419b20f047b