[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 try#afeffcd090fe6cee35c99f8b5539d74aa443fe34 for pr-140956
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcallumthomson%2Frust-hangman" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[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-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/callumthomson/rust-hangman on toolchain afeffcd090fe6cee35c99f8b5539d74aa443fe34
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+afeffcd090fe6cee35c99f8b5539d74aa443fe34" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/callumthomson/rust-hangman already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+afeffcd090fe6cee35c99f8b5539d74aa443fe34" "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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+afeffcd090fe6cee35c99f8b5539d74aa443fe34" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9a0f85304a9b9e2d3afb0ce7cb4b9e257f296ecd707f88c093ba7b9fe110d653
[INFO] running `Command { std: "docker" "start" "-a" "9a0f85304a9b9e2d3afb0ce7cb4b9e257f296ecd707f88c093ba7b9fe110d653", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9a0f85304a9b9e2d3afb0ce7cb4b9e257f296ecd707f88c093ba7b9fe110d653", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a0f85304a9b9e2d3afb0ce7cb4b9e257f296ecd707f88c093ba7b9fe110d653", kill_on_drop: false }`
[INFO] [stdout] 9a0f85304a9b9e2d3afb0ce7cb4b9e257f296ecd707f88c093ba7b9fe110d653
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+afeffcd090fe6cee35c99f8b5539d74aa443fe34" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] beca625b91ac79b79c02e6acfa3d688932a377cc4129c6aec7e9cd45fc4f7f35
[INFO] running `Command { std: "docker" "start" "-a" "beca625b91ac79b79c02e6acfa3d688932a377cc4129c6aec7e9cd45fc4f7f35", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]    Compiling autocfg v0.1.1
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling libc v0.2.46
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.4
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking rand_os v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.1
[INFO] [stderr]     Checking hangman v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `word` is never read
[INFO] [stdout]   --> src/filereader.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub struct FileReader
[INFO] [stdout]    |            ---------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 10 |     pub word: Vec<char>,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[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: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 131 |                 let _ = mem::replace(&mut self.dashed_word[i], character);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `word` is never read
[INFO] [stdout]   --> src/filereader.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub struct FileReader
[INFO] [stdout]    |            ---------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 10 |     pub word: Vec<char>,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[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: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 131 |                 let _ = mem::replace(&mut self.dashed_word[i], character);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.07s
[INFO] running `Command { std: "docker" "inspect" "beca625b91ac79b79c02e6acfa3d688932a377cc4129c6aec7e9cd45fc4f7f35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "beca625b91ac79b79c02e6acfa3d688932a377cc4129c6aec7e9cd45fc4f7f35", kill_on_drop: false }`
[INFO] [stdout] beca625b91ac79b79c02e6acfa3d688932a377cc4129c6aec7e9cd45fc4f7f35