[INFO] fetching crate piecetable 0.2.1...
[INFO] checking piecetable-0.2.1 against master#bbe853615821442ef11d6cd42a30a73432b38d89 for pr-154205
[INFO] extracting crate piecetable 0.2.1 into /workspace/builds/worker-3-tc1/source
[INFO] started tweaking crates.io crate piecetable 0.2.1
[INFO] finished tweaking crates.io crate piecetable 0.2.1
[INFO] tweaked toml for crates.io crate piecetable 0.2.1 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate piecetable 0.2.1 on toolchain bbe853615821442ef11d6cd42a30a73432b38d89
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bbe853615821442ef11d6cd42a30a73432b38d89" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bbe853615821442ef11d6cd42a30a73432b38d89" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bbe853615821442ef11d6cd42a30a73432b38d89" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+bbe853615821442ef11d6cd42a30a73432b38d89" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 807bd64c164dde1c129c4d7ddeddc913a4a09f0782d7c9616740380114579b69
[INFO] running `Command { std: "docker" "start" "-a" "807bd64c164dde1c129c4d7ddeddc913a4a09f0782d7c9616740380114579b69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "807bd64c164dde1c129c4d7ddeddc913a4a09f0782d7c9616740380114579b69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "807bd64c164dde1c129c4d7ddeddc913a4a09f0782d7c9616740380114579b69", kill_on_drop: false }`
[INFO] [stdout] 807bd64c164dde1c129c4d7ddeddc913a4a09f0782d7c9616740380114579b69
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+bbe853615821442ef11d6cd42a30a73432b38d89" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e92a5aafad13a689d829914899fe5508ed073a62fe2407b9c7396fa4f6e54afe
[INFO] running `Command { std: "docker" "start" "-a" "e92a5aafad13a689d829914899fe5508ed073a62fe2407b9c7396fa4f6e54afe", kill_on_drop: false }`
[INFO] [stderr]     Checking piecetable v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:254:13
[INFO] [stdout]     |
[INFO] [stdout] 254 |         let mut piece = &mut self.pieces[piece_index];
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:254:13
[INFO] [stdout]     |
[INFO] [stdout] 254 |         let mut piece = &mut self.pieces[piece_index];
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.31s
[INFO] running `Command { std: "docker" "inspect" "e92a5aafad13a689d829914899fe5508ed073a62fe2407b9c7396fa4f6e54afe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e92a5aafad13a689d829914899fe5508ed073a62fe2407b9c7396fa4f6e54afe", kill_on_drop: false }`
[INFO] [stdout] e92a5aafad13a689d829914899fe5508ed073a62fe2407b9c7396fa4f6e54afe