[INFO] cloning repository https://github.com/Ermain-12/Introduction-to-Rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Ermain-12/Introduction-to-Rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 19db755187092c11f3f3ea13092682fc7bc92786
[INFO] checking Ermain-12/Introduction-to-Rust against try#3d9fdbff4f377de96b3a51174e7a64086bee9a5c for pr-81477
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust" "/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/Ermain-12/Introduction-to-Rust on toolchain 3d9fdbff4f377de96b3a51174e7a64086bee9a5c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Ermain-12/Introduction-to-Rust
[INFO] finished tweaking git repo https://github.com/Ermain-12/Introduction-to-Rust
[INFO] tweaked toml for git repo https://github.com/Ermain-12/Introduction-to-Rust written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/Ermain-12/Introduction-to-Rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "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/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8b5b2df8a217b83cd0e7fffe44c8883f5e99d2d268b35df26d5308490af9549d
[INFO] running `Command { std: "docker" "start" "-a" "8b5b2df8a217b83cd0e7fffe44c8883f5e99d2d268b35df26d5308490af9549d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8b5b2df8a217b83cd0e7fffe44c8883f5e99d2d268b35df26d5308490af9549d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8b5b2df8a217b83cd0e7fffe44c8883f5e99d2d268b35df26d5308490af9549d", kill_on_drop: false }`
[INFO] [stdout] 8b5b2df8a217b83cd0e7fffe44c8883f5e99d2d268b35df26d5308490af9549d
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 42387eaecc6c566ac7f774f5d0ca6dc4c26bb5e8111538314548b951727f86f5
[INFO] running `Command { std: "docker" "start" "-a" "42387eaecc6c566ac7f774f5d0ca6dc4c26bb5e8111538314548b951727f86f5", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.40
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]    Compiling regex v1.0.0
[INFO] [stderr]     Checking lazy_static v1.0.0
[INFO] [stderr]     Checking ucd-util v0.1.1
[INFO] [stderr]     Checking utf8-ranges v1.0.0
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]     Checking thread_local v0.3.5
[INFO] [stderr]     Checking regex-syntax v0.6.0
[INFO] [stderr]     Checking memchr v2.0.1
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking aho-corasick v0.6.4
[INFO] [stderr]     Checking hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |    let mut twenty_one = my_vec.pop();
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |    let mut twenty_one = my_vec.pop();
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.46s
[INFO] running `Command { std: "docker" "inspect" "42387eaecc6c566ac7f774f5d0ca6dc4c26bb5e8111538314548b951727f86f5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42387eaecc6c566ac7f774f5d0ca6dc4c26bb5e8111538314548b951727f86f5", kill_on_drop: false }`
[INFO] [stdout] 42387eaecc6c566ac7f774f5d0ca6dc4c26bb5e8111538314548b951727f86f5