[INFO] cloning repository https://github.com/mlemesle/word_tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mlemesle/word_tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmlemesle%2Fword_tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmlemesle%2Fword_tree'...
[INFO] [stderr] /workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmlemesle%2Fword_tree/branches/: No space left on device
[WARN] Retrying crate fetch in 3 seconds (attempt 1)
[INFO] cloning repository https://github.com/mlemesle/word_tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mlemesle/word_tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmlemesle%2Fword_tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmlemesle%2Fword_tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] efe72a7e43aac36cc292df8617018c1b1bf22910
[INFO] checking mlemesle/word_tree against master#249cb84316401daf040832cdbb8a45e0f5ab6af8 for pr-138438
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmlemesle%2Fword_tree" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mlemesle/word_tree on toolchain 249cb84316401daf040832cdbb8a45e0f5ab6af8
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+249cb84316401daf040832cdbb8a45e0f5ab6af8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mlemesle/word_tree
[INFO] finished tweaking git repo https://github.com/mlemesle/word_tree
[INFO] tweaked toml for git repo https://github.com/mlemesle/word_tree written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/mlemesle/word_tree 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" "+249cb84316401daf040832cdbb8a45e0f5ab6af8" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+249cb84316401daf040832cdbb8a45e0f5ab6af8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 33d7466438e4cef91ae6ff9bcf5bd47ca32d90b518ac21eb7249c9e221705b78
[INFO] running `Command { std: "docker" "start" "-a" "33d7466438e4cef91ae6ff9bcf5bd47ca32d90b518ac21eb7249c9e221705b78", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "33d7466438e4cef91ae6ff9bcf5bd47ca32d90b518ac21eb7249c9e221705b78", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "33d7466438e4cef91ae6ff9bcf5bd47ca32d90b518ac21eb7249c9e221705b78", kill_on_drop: false }`
[INFO] [stdout] 33d7466438e4cef91ae6ff9bcf5bd47ca32d90b518ac21eb7249c9e221705b78
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+249cb84316401daf040832cdbb8a45e0f5ab6af8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6fd39cea2a426681740364bc471e6b92f3c05dc104dd0e9f60eeb8b2636ae72e
[INFO] running `Command { std: "docker" "start" "-a" "6fd39cea2a426681740364bc471e6b92f3c05dc104dd0e9f60eeb8b2636ae72e", kill_on_drop: false }`
[INFO] [stderr]     Checking word_tree v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: method `print` is never used
[INFO] [stdout]   --> src/tree/tree.rs:75:12
[INFO] [stdout]    |
[INFO] [stdout] 52 | impl TreeWord {
[INFO] [stdout]    | ------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 75 |     pub fn print(self) {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/tree/tree.rs:39:17
[INFO] [stdout]    |
[INFO] [stdout] 39 |                 &v.to_graph(depth+1);
[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] 39 |                 let _ = &v.to_graph(depth+1);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/tree/tree.rs:82:13
[INFO] [stdout]    |
[INFO] [stdout] 82 |             &v.generate_labels(0);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 82 |             let _ = &v.generate_labels(0);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `print` is never used
[INFO] [stdout]   --> src/tree/tree.rs:75:12
[INFO] [stdout]    |
[INFO] [stdout] 52 | impl TreeWord {
[INFO] [stdout]    | ------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 75 |     pub fn print(self) {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/tree/tree.rs:39:17
[INFO] [stdout]    |
[INFO] [stdout] 39 |                 &v.to_graph(depth+1);
[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] 39 |                 let _ = &v.to_graph(depth+1);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/tree/tree.rs:82:13
[INFO] [stdout]    |
[INFO] [stdout] 82 |             &v.generate_labels(0);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 82 |             let _ = &v.generate_labels(0);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.05s
[INFO] running `Command { std: "docker" "inspect" "6fd39cea2a426681740364bc471e6b92f3c05dc104dd0e9f60eeb8b2636ae72e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6fd39cea2a426681740364bc471e6b92f3c05dc104dd0e9f60eeb8b2636ae72e", kill_on_drop: false }`
[INFO] [stdout] 6fd39cea2a426681740364bc471e6b92f3c05dc104dd0e9f60eeb8b2636ae72e