[INFO] cloning repository https://github.com/tnas/word-ladder
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tnas/word-ladder" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 86e71e4bccf17ddb8652deb58a3bfa36748cfa10
[INFO] testing tnas/word-ladder against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tnas/word-ladder on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tnas/word-ladder
[INFO] finished tweaking git repo https://github.com/tnas/word-ladder
[INFO] tweaked toml for git repo https://github.com/tnas/word-ladder written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/tnas/word-ladder already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1d442726792aeec3c6ad8670f01751fb75e59fd8d7d12c64f71b6d12b4757472
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "1d442726792aeec3c6ad8670f01751fb75e59fd8d7d12c64f71b6d12b4757472", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1d442726792aeec3c6ad8670f01751fb75e59fd8d7d12c64f71b6d12b4757472", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1d442726792aeec3c6ad8670f01751fb75e59fd8d7d12c64f71b6d12b4757472", kill_on_drop: false }`
[INFO] [stdout] 1d442726792aeec3c6ad8670f01751fb75e59fd8d7d12c64f71b6d12b4757472
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 604a446cb7c65348524c7c917c470433bc267e41fa639ec568f9da10670ec991
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "604a446cb7c65348524c7c917c470433bc267e41fa639ec568f9da10670ec991", kill_on_drop: false }`
[INFO] [stderr]    Compiling const_fn v0.4.2
[INFO] [stderr]    Compiling crossbeam-utils v0.8.0
[INFO] [stderr]    Compiling word-ladder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:179:9
[INFO] [stdout]     |
[INFO] [stdout] 179 |     let mut word_levels: Vec<RwLock<usize>> = std::iter::repeat_with(|| RwLock::new(usize::MAX)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:183:9
[INFO] [stdout]     |
[INFO] [stdout] 183 |     let mut level_checked_to_die: Vec<RwLock<bool>> = std::iter::repeat_with(|| RwLock::new(false)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.94s
[INFO] running `Command { std: "docker" "inspect" "604a446cb7c65348524c7c917c470433bc267e41fa639ec568f9da10670ec991", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "604a446cb7c65348524c7c917c470433bc267e41fa639ec568f9da10670ec991", kill_on_drop: false }`
[INFO] [stdout] 604a446cb7c65348524c7c917c470433bc267e41fa639ec568f9da10670ec991
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7b2746a4208d34f55c73bb3cdb88ea9084be45765122205fa93cbe6089e5f7ae
[INFO] running `Command { std: "docker" "start" "-a" "7b2746a4208d34f55c73bb3cdb88ea9084be45765122205fa93cbe6089e5f7ae", kill_on_drop: false }`
[INFO] [stderr]    Compiling word-ladder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:179:9
[INFO] [stdout]     |
[INFO] [stdout] 179 |     let mut word_levels: Vec<RwLock<usize>> = std::iter::repeat_with(|| RwLock::new(usize::MAX)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ang.rs:183:9
[INFO] [stdout]     |
[INFO] [stdout] 183 |     let mut level_checked_to_die: Vec<RwLock<bool>> = std::iter::repeat_with(|| RwLock::new(false)).take(n_words).collect();
[INFO] [stdout]     |         ----^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.10s
[INFO] running `Command { std: "docker" "inspect" "7b2746a4208d34f55c73bb3cdb88ea9084be45765122205fa93cbe6089e5f7ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b2746a4208d34f55c73bb3cdb88ea9084be45765122205fa93cbe6089e5f7ae", kill_on_drop: false }`
[INFO] [stdout] 7b2746a4208d34f55c73bb3cdb88ea9084be45765122205fa93cbe6089e5f7ae
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 46586ceab8b25899aacd1cf0e55030094ac5d8bc9e25ab9ad41bd0a3a56b3f76
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "46586ceab8b25899aacd1cf0e55030094ac5d8bc9e25ab9ad41bd0a3a56b3f76", kill_on_drop: false }`
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/ang.rs:179:9
[INFO] [stderr]     |
[INFO] [stderr] 179 |     let mut word_levels: Vec<RwLock<usize>> = std::iter::repeat_with(|| RwLock::new(usize::MAX)).take(n_words).collect();
[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/ang.rs:183:9
[INFO] [stderr]     |
[INFO] [stderr] 183 |     let mut level_checked_to_die: Vec<RwLock<bool>> = std::iter::repeat_with(|| RwLock::new(false)).take(n_words).collect();
[INFO] [stderr]     |         ----^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/word_ladder-b501face98424213
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "46586ceab8b25899aacd1cf0e55030094ac5d8bc9e25ab9ad41bd0a3a56b3f76", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "46586ceab8b25899aacd1cf0e55030094ac5d8bc9e25ab9ad41bd0a3a56b3f76", kill_on_drop: false }`
[INFO] [stdout] 46586ceab8b25899aacd1cf0e55030094ac5d8bc9e25ab9ad41bd0a3a56b3f76