[INFO] fetching crate libgrep-rs 0.1.4...
[INFO] checking libgrep-rs-0.1.4 against try#f6e2f78768c57172b99c3e85892f867894dc7e30 for pr-75502
[INFO] extracting crate libgrep-rs 0.1.4 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate libgrep-rs 0.1.4 on toolchain f6e2f78768c57172b99c3e85892f867894dc7e30
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate libgrep-rs 0.1.4
[INFO] finished tweaking crates.io crate libgrep-rs 0.1.4
[INFO] tweaked toml for crates.io crate libgrep-rs 0.1.4 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate libgrep-rs 0.1.4 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "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:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 44389d9c99861393b1892b8ee281a05442b5240ae0226eda221fcde0a522ef04
[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" "44389d9c99861393b1892b8ee281a05442b5240ae0226eda221fcde0a522ef04", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "44389d9c99861393b1892b8ee281a05442b5240ae0226eda221fcde0a522ef04", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "44389d9c99861393b1892b8ee281a05442b5240ae0226eda221fcde0a522ef04", kill_on_drop: false }`
[INFO] [stdout] 44389d9c99861393b1892b8ee281a05442b5240ae0226eda221fcde0a522ef04
[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:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+f6e2f78768c57172b99c3e85892f867894dc7e30" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6b4a0201a24e088357c49d253e8268b153aba8274b554855cf163deac0c0ad78
[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" "6b4a0201a24e088357c49d253e8268b153aba8274b554855cf163deac0c0ad78", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking regex-syntax v0.6.17
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.10
[INFO] [stderr]     Checking regex v1.3.7
[INFO] [stderr]     Checking libgrep-rs v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:179:13
[INFO] [stdout]     |
[INFO] [stdout] 179 |         let mut return_text: String = searcher.search();
[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 8.27s
[INFO] running `Command { std: "docker" "inspect" "6b4a0201a24e088357c49d253e8268b153aba8274b554855cf163deac0c0ad78", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b4a0201a24e088357c49d253e8268b153aba8274b554855cf163deac0c0ad78", kill_on_drop: false }`
[INFO] [stdout] 6b4a0201a24e088357c49d253e8268b153aba8274b554855cf163deac0c0ad78