[INFO] cloning repository https://github.com/callumthomson/rust-hangman
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/callumthomson/rust-hangman" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcallumthomson%2Frust-hangman", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcallumthomson%2Frust-hangman'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2f3754e5ae880ca837f7ada3eb76554a9a396ec1
[INFO] checking callumthomson/rust-hangman against master#c9228570668803e3e6402770d55f23a12c9ae686 for pr-79472
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcallumthomson%2Frust-hangman" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/callumthomson/rust-hangman on toolchain c9228570668803e3e6402770d55f23a12c9ae686
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c9228570668803e3e6402770d55f23a12c9ae686" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/callumthomson/rust-hangman
[INFO] finished tweaking git repo https://github.com/callumthomson/rust-hangman
[INFO] tweaked toml for git repo https://github.com/callumthomson/rust-hangman written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/callumthomson/rust-hangman already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c9228570668803e3e6402770d55f23a12c9ae686" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+c9228570668803e3e6402770d55f23a12c9ae686" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2168398dee88645b108383902e3bcb52c1ac5cdd5b5f73ff360a10f1dc812f46
[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" "2168398dee88645b108383902e3bcb52c1ac5cdd5b5f73ff360a10f1dc812f46", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2168398dee88645b108383902e3bcb52c1ac5cdd5b5f73ff360a10f1dc812f46", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2168398dee88645b108383902e3bcb52c1ac5cdd5b5f73ff360a10f1dc812f46", kill_on_drop: false }`
[INFO] [stdout] 2168398dee88645b108383902e3bcb52c1ac5cdd5b5f73ff360a10f1dc812f46
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+c9228570668803e3e6402770d55f23a12c9ae686" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cb5c93ec23466e8150e0bb25b9d47718ae1f0892af674062a72c9ae7a4685701
[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" "cb5c93ec23466e8150e0bb25b9d47718ae1f0892af674062a72c9ae7a4685701", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]    Compiling libc v0.2.46
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.4
[INFO] [stderr]    Compiling rand_pcg v0.1.1
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_os v0.1.1
[INFO] [stderr]     Checking hangman v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/hangman.rs:131:17
[INFO] [stdout]     |
[INFO] [stdout] 131 |                 mem::replace(&mut self.dashed_word[i], character);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/hangman.rs:131:17
[INFO] [stdout]     |
[INFO] [stdout] 131 |                 mem::replace(&mut self.dashed_word[i], character);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 10.15s
[INFO] running `Command { std: "docker" "inspect" "cb5c93ec23466e8150e0bb25b9d47718ae1f0892af674062a72c9ae7a4685701", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cb5c93ec23466e8150e0bb25b9d47718ae1f0892af674062a72c9ae7a4685701", kill_on_drop: false }`
[INFO] [stdout] cb5c93ec23466e8150e0bb25b9d47718ae1f0892af674062a72c9ae7a4685701