[INFO] fetching crate syswall 0.3.1...
[INFO] checking syswall-0.3.1 against try#998b6603a58e47f42ccce7a67943234e96b6839e for pr-143170
[INFO] extracting crate syswall 0.3.1 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate syswall 0.3.1
[INFO] finished tweaking crates.io crate syswall 0.3.1
[INFO] tweaked toml for crates.io crate syswall 0.3.1 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate syswall 0.3.1 on toolchain 998b6603a58e47f42ccce7a67943234e96b6839e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "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" "+998b6603a58e47f42ccce7a67943234e96b6839e" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 20 packages to latest compatible versions
[INFO] [stderr]       Adding nix v0.13.1 (available: v0.30.1)
[INFO] [stderr]       Adding signal-hook v0.1.17 (available: v0.3.18)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 84f644355945a182f446415323de58dfe9a05d885e1db1dd2a7148125ab22be7
[INFO] running `Command { std: "docker" "start" "-a" "84f644355945a182f446415323de58dfe9a05d885e1db1dd2a7148125ab22be7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "84f644355945a182f446415323de58dfe9a05d885e1db1dd2a7148125ab22be7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84f644355945a182f446415323de58dfe9a05d885e1db1dd2a7148125ab22be7", kill_on_drop: false }`
[INFO] [stdout] 84f644355945a182f446415323de58dfe9a05d885e1db1dd2a7148125ab22be7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 368df2c96699ed38c534afc8bfa6810fea3f31dc44a7e6a07522cba4b20e903d
[INFO] running `Command { std: "docker" "start" "-a" "368df2c96699ed38c534afc8bfa6810fea3f31dc44a7e6a07522cba4b20e903d", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.95
[INFO] [stderr]    Compiling nix v0.13.1
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking signal-hook-registry v1.4.5
[INFO] [stderr]     Checking signal-hook v0.1.17
[INFO] [stderr]    Compiling quote v1.0.40
[INFO] [stderr]    Compiling syn v2.0.104
[INFO] [stderr]    Compiling serde_derive v1.0.219
[INFO] [stderr]     Checking serde v1.0.219
[INFO] [stderr]     Checking serde_json v1.0.140
[INFO] [stderr]     Checking syswall v0.3.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/child_process.rs:300:17
[INFO] [stdout]     |
[INFO] [stdout] 300 |             let mut child = processes.0.get_mut(&pid).ok_or_else(|| format!(
[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/child_process.rs:418:32
[INFO] [stdout]     |
[INFO] [stdout] 418 |             } else if let Some(mut child) = processes.0.get_mut(&pid) {
[INFO] [stdout]     |                                ----^^^^^
[INFO] [stdout]     |                                |
[INFO] [stdout]     |                                help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/child_process.rs:300:17
[INFO] [stdout]     |
[INFO] [stdout] 300 |             let mut child = processes.0.get_mut(&pid).ok_or_else(|| format!(
[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/child_process.rs:418:32
[INFO] [stdout]     |
[INFO] [stdout] 418 |             } else if let Some(mut child) = processes.0.get_mut(&pid) {
[INFO] [stdout]     |                                ----^^^^^
[INFO] [stdout]     |                                |
[INFO] [stdout]     |                                help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 13.35s
[INFO] running `Command { std: "docker" "inspect" "368df2c96699ed38c534afc8bfa6810fea3f31dc44a7e6a07522cba4b20e903d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "368df2c96699ed38c534afc8bfa6810fea3f31dc44a7e6a07522cba4b20e903d", kill_on_drop: false }`
[INFO] [stdout] 368df2c96699ed38c534afc8bfa6810fea3f31dc44a7e6a07522cba4b20e903d