[INFO] fetching crate stperf 0.1.4...
[INFO] checking stperf-0.1.4 against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] extracting crate stperf 0.1.4 into /workspace/builds/worker-15/source
[INFO] validating manifest of crates.io crate stperf 0.1.4 on toolchain cac44d9528e3bbbdaa1537d187bd489ccc5de18c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate stperf 0.1.4
[INFO] finished tweaking crates.io crate stperf 0.1.4
[INFO] tweaked toml for crates.io crate stperf 0.1.4 written to /workspace/builds/worker-15/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "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-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5503a0e3b864231f90fdf11a526e1943db5976a2ae33e7d32554a2f18450361f
[INFO] running `Command { std: "docker" "start" "-a" "5503a0e3b864231f90fdf11a526e1943db5976a2ae33e7d32554a2f18450361f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5503a0e3b864231f90fdf11a526e1943db5976a2ae33e7d32554a2f18450361f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5503a0e3b864231f90fdf11a526e1943db5976a2ae33e7d32554a2f18450361f", kill_on_drop: false }`
[INFO] [stdout] 5503a0e3b864231f90fdf11a526e1943db5976a2ae33e7d32554a2f18450361f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dd42ddc4d6023a4ac4cdaf80cac1ad389f9e6d290d6bdc5a08051c35a679f674
[INFO] running `Command { std: "docker" "start" "-a" "dd42ddc4d6023a4ac4cdaf80cac1ad389f9e6d290d6bdc5a08051c35a679f674", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking stperf v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/measurement.rs:227:17
[INFO] [stdout]     |
[INFO] [stdout] 227 |             let mut child_lock = child.get_mut();
[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: variable does not need to be mutable
[INFO] [stdout]    --> src/measurement.rs:227:17
[INFO] [stdout]     |
[INFO] [stdout] 227 |             let mut child_lock = child.get_mut();
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.44s
[INFO] running `Command { std: "docker" "inspect" "dd42ddc4d6023a4ac4cdaf80cac1ad389f9e6d290d6bdc5a08051c35a679f674", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd42ddc4d6023a4ac4cdaf80cac1ad389f9e6d290d6bdc5a08051c35a679f674", kill_on_drop: false }`
[INFO] [stdout] dd42ddc4d6023a4ac4cdaf80cac1ad389f9e6d290d6bdc5a08051c35a679f674