[INFO] fetching crate pack_2048 0.4.4...
[INFO] checking pack_2048-0.4.4 against master#33fdb797f59421c7bbecaa4588ed5d7a31a9494a for pr-87190-3
[INFO] extracting crate pack_2048 0.4.4 into /workspace/builds/worker-45/source
[INFO] validating manifest of crates.io crate pack_2048 0.4.4 on toolchain 33fdb797f59421c7bbecaa4588ed5d7a31a9494a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate pack_2048 0.4.4
[INFO] finished tweaking crates.io crate pack_2048 0.4.4
[INFO] tweaked toml for crates.io crate pack_2048 0.4.4 written to /workspace/builds/worker-45/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "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" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded numtoa v0.1.0
[INFO] [stderr]   Downloaded termion v1.5.6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-45/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-45/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 49e74815057d29f382c9a87a602f720bcba78fc788a64d1a3e6fc9e430827386
[INFO] running `Command { std: "docker" "start" "-a" "49e74815057d29f382c9a87a602f720bcba78fc788a64d1a3e6fc9e430827386", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "49e74815057d29f382c9a87a602f720bcba78fc788a64d1a3e6fc9e430827386", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "49e74815057d29f382c9a87a602f720bcba78fc788a64d1a3e6fc9e430827386", kill_on_drop: false }`
[INFO] [stdout] 49e74815057d29f382c9a87a602f720bcba78fc788a64d1a3e6fc9e430827386
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-45/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-45/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c80924fe2ea34cb2c8f9f700ba4f468b0feb7bfa8bfb31f77d1aa7d558a5ae9f
[INFO] running `Command { std: "docker" "start" "-a" "c80924fe2ea34cb2c8f9f700ba4f468b0feb7bfa8bfb31f77d1aa7d558a5ae9f", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.100
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]     Checking pack_2048 v0.4.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:105:13
[INFO] [stdout]     |
[INFO] [stdout] 105 |         for mut row in &mut board.iter_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/lib.rs:105:13
[INFO] [stdout]     |
[INFO] [stdout] 105 |         for mut row in &mut board.iter_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/lib.rs:165:13
[INFO] [stdout]     |
[INFO] [stdout] 165 |         for mut row in &mut board.iter_mut() {
[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/lib.rs:165:13
[INFO] [stdout]     |
[INFO] [stdout] 165 |         for mut row in &mut board.iter_mut() {
[INFO] [stdout]     |             ----^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.93s
[INFO] running `Command { std: "docker" "inspect" "c80924fe2ea34cb2c8f9f700ba4f468b0feb7bfa8bfb31f77d1aa7d558a5ae9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c80924fe2ea34cb2c8f9f700ba4f468b0feb7bfa8bfb31f77d1aa7d558a5ae9f", kill_on_drop: false }`
[INFO] [stdout] c80924fe2ea34cb2c8f9f700ba4f468b0feb7bfa8bfb31f77d1aa7d558a5ae9f