[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 master#5d5ff84130da0d74c6ece368dbe821d8f83fa526 for pr-79296
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftnas%2Fword-ladder" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tnas/word-ladder on toolchain 5d5ff84130da0d74c6ece368dbe821d8f83fa526
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "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-6/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" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a8d493b79d248b160f0612c92975a5434d9b1d2578d3f3c2f4071b5d31c62200
[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" "a8d493b79d248b160f0612c92975a5434d9b1d2578d3f3c2f4071b5d31c62200", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a8d493b79d248b160f0612c92975a5434d9b1d2578d3f3c2f4071b5d31c62200", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a8d493b79d248b160f0612c92975a5434d9b1d2578d3f3c2f4071b5d31c62200", kill_on_drop: false }`
[INFO] [stdout] a8d493b79d248b160f0612c92975a5434d9b1d2578d3f3c2f4071b5d31c62200
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=forbid" "-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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 691f81ec15bb8fe0fc4a77e7315519cca33c07a15e571415a4d2c1708ef3dc09
[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" "691f81ec15bb8fe0fc4a77e7315519cca33c07a15e571415a4d2c1708ef3dc09", 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 4.35s
[INFO] running `Command { std: "docker" "inspect" "691f81ec15bb8fe0fc4a77e7315519cca33c07a15e571415a4d2c1708ef3dc09", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "691f81ec15bb8fe0fc4a77e7315519cca33c07a15e571415a4d2c1708ef3dc09", kill_on_drop: false }`
[INFO] [stdout] 691f81ec15bb8fe0fc4a77e7315519cca33c07a15e571415a4d2c1708ef3dc09
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=forbid" "-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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "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] 564052dd230d09ea9f81ded011337004ebe9fca6fb85a6e018a3aae832f7ac69
[INFO] running `Command { std: "docker" "start" "-a" "564052dd230d09ea9f81ded011337004ebe9fca6fb85a6e018a3aae832f7ac69", 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 0.60s
[INFO] running `Command { std: "docker" "inspect" "564052dd230d09ea9f81ded011337004ebe9fca6fb85a6e018a3aae832f7ac69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "564052dd230d09ea9f81ded011337004ebe9fca6fb85a6e018a3aae832f7ac69", kill_on_drop: false }`
[INFO] [stdout] 564052dd230d09ea9f81ded011337004ebe9fca6fb85a6e018a3aae832f7ac69
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=forbid" "-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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 304556575b51e09e1a65ea8fe3528d53723ca3f373d4b1be34ad7bfbb42464cd
[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" "304556575b51e09e1a65ea8fe3528d53723ca3f373d4b1be34ad7bfbb42464cd", 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 0.05s
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/word_ladder-4a30d2e77b2e254f
[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" "304556575b51e09e1a65ea8fe3528d53723ca3f373d4b1be34ad7bfbb42464cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "304556575b51e09e1a65ea8fe3528d53723ca3f373d4b1be34ad7bfbb42464cd", kill_on_drop: false }`
[INFO] [stdout] 304556575b51e09e1a65ea8fe3528d53723ca3f373d4b1be34ad7bfbb42464cd