[INFO] cloning repository https://github.com/ameernormie/rust_lang_concepts
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ameernormie/rust_lang_concepts" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fameernormie%2Frust_lang_concepts", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fameernormie%2Frust_lang_concepts'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 52dff83aa55dc7b9d9fd4db48c90582247359856
[INFO] checking ameernormie/rust_lang_concepts against try#b2c2190fa7bf856bb0ed5e8806266e3a2135c6f8 for pr-78363
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fameernormie%2Frust_lang_concepts" "/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/ameernormie/rust_lang_concepts on toolchain b2c2190fa7bf856bb0ed5e8806266e3a2135c6f8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2c2190fa7bf856bb0ed5e8806266e3a2135c6f8" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ameernormie/rust_lang_concepts
[INFO] finished tweaking git repo https://github.com/ameernormie/rust_lang_concepts
[INFO] tweaked toml for git repo https://github.com/ameernormie/rust_lang_concepts written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/ameernormie/rust_lang_concepts already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2c2190fa7bf856bb0ed5e8806266e3a2135c6f8" "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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b2c2190fa7bf856bb0ed5e8806266e3a2135c6f8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 621017f5e7d6088336e83509b17118e6257d79d1897dccc73dfe54d05a1f04ef
[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" "621017f5e7d6088336e83509b17118e6257d79d1897dccc73dfe54d05a1f04ef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "621017f5e7d6088336e83509b17118e6257d79d1897dccc73dfe54d05a1f04ef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "621017f5e7d6088336e83509b17118e6257d79d1897dccc73dfe54d05a1f04ef", kill_on_drop: false }`
[INFO] [stdout] 621017f5e7d6088336e83509b17118e6257d79d1897dccc73dfe54d05a1f04ef
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b2c2190fa7bf856bb0ed5e8806266e3a2135c6f8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d83aa68833638f759e3e6822002da32f183c53477f9dc46c6c5d2d1ede00d743
[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" "d83aa68833638f759e3e6822002da32f183c53477f9dc46c6c5d2d1ede00d743", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_lang_concepts v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `v1`
[INFO] [stdout]   --> src/closures.rs:90:9
[INFO] [stdout]    |
[INFO] [stdout] 90 |     let v1 = c.value(1);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `LimitTracker`
[INFO] [stdout]   --> src/smart_pointers.rs:73:12
[INFO] [stdout]    |
[INFO] [stdout] 73 | pub struct LimitTracker<'a, T: Messenger> {
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/smart_pointers.rs:83:12
[INFO] [stdout]    |
[INFO] [stdout] 83 |     pub fn new(messenger: &T, max: usize) -> LimitTracker<T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `set_value`
[INFO] [stdout]   --> src/smart_pointers.rs:91:12
[INFO] [stdout]    |
[INFO] [stdout] 91 |     pub fn set_value(&mut self, value: usize) {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `Command { std: "docker" "inspect" "d83aa68833638f759e3e6822002da32f183c53477f9dc46c6c5d2d1ede00d743", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d83aa68833638f759e3e6822002da32f183c53477f9dc46c6c5d2d1ede00d743", kill_on_drop: false }`
[INFO] [stdout] d83aa68833638f759e3e6822002da32f183c53477f9dc46c6c5d2d1ede00d743