[INFO] updating cached 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" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 19db755187092c11f3f3ea13092682fc7bc92786
[INFO] checking Ermain-12/Introduction-to-Rust against master#4fb54ed484e2239a3e9eff3be17df00d2a162be3 for pr-73345
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Ermain-12/Introduction-to-Rust on toolchain 4fb54ed484e2239a3e9eff3be17df00d2a162be3
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "read-manifest" "--manifest-path" "Cargo.toml", 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-8/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" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9a5dacf61d18a2b73a26d02d09146b6fc8bf25c51e6af478c57c1ea3b66a4531
[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" "9a5dacf61d18a2b73a26d02d09146b6fc8bf25c51e6af478c57c1ea3b66a4531", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9a5dacf61d18a2b73a26d02d09146b6fc8bf25c51e6af478c57c1ea3b66a4531", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a5dacf61d18a2b73a26d02d09146b6fc8bf25c51e6af478c57c1ea3b66a4531", kill_on_drop: false }`
[INFO] [stdout] 9a5dacf61d18a2b73a26d02d09146b6fc8bf25c51e6af478c57c1ea3b66a4531
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 820cca41c12355780dc40f73ff46cfc54a3b6c12fcc10d4ab340ea0c77e96c8e
[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" "820cca41c12355780dc40f73ff46cfc54a3b6c12fcc10d4ab340ea0c77e96c8e", kill_on_drop: false }`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking memchr v2.0.1
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking regex-syntax v0.6.0
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]     Checking aho-corasick v0.6.4
[INFO] [stderr]     Checking thread_local v0.3.5
[INFO] [stderr]     Checking regex v1.0.0
[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 8.25s
[INFO] running `Command { std: "docker" "inspect" "820cca41c12355780dc40f73ff46cfc54a3b6c12fcc10d4ab340ea0c77e96c8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "820cca41c12355780dc40f73ff46cfc54a3b6c12fcc10d4ab340ea0c77e96c8e", kill_on_drop: false }`
[INFO] [stdout] 820cca41c12355780dc40f73ff46cfc54a3b6c12fcc10d4ab340ea0c77e96c8e