[INFO] fetching crate pack_2048 0.4.4...
[INFO] checking pack_2048-0.4.4 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate pack_2048 0.4.4 into /workspace/builds/worker-5-tc1/source
[INFO] validating manifest of crates.io crate pack_2048 0.4.4 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "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-5-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 15 packages
[INFO] [stderr]       Adding bitflags v1.3.2 (latest: v2.5.0)
[INFO] [stderr]       Adding cloudabi v0.0.3 (latest: v0.1.0)
[INFO] [stderr]       Adding numtoa v0.1.0 (latest: v0.2.4)
[INFO] [stderr]       Adding rand v0.5.6 (latest: v0.8.5)
[INFO] [stderr]       Adding rand_core v0.3.1 (latest: v0.6.4)
[INFO] [stderr]       Adding rand_core v0.4.2 (latest: v0.6.4)
[INFO] [stderr]       Adding redox_syscall v0.2.16 (latest: v0.5.1)
[INFO] [stderr]       Adding termion v1.5.6 (latest: v3.0.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded termion v1.5.6
[INFO] [stderr]   Downloaded redox_termios v0.1.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e27f2cf8ca643ec7d3e3577ae49359ecb4e734c9d357ccd37559a5df0d31ebcf
[INFO] running `Command { std: "docker" "start" "-a" "e27f2cf8ca643ec7d3e3577ae49359ecb4e734c9d357ccd37559a5df0d31ebcf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e27f2cf8ca643ec7d3e3577ae49359ecb4e734c9d357ccd37559a5df0d31ebcf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e27f2cf8ca643ec7d3e3577ae49359ecb4e734c9d357ccd37559a5df0d31ebcf", kill_on_drop: false }`
[INFO] [stdout] e27f2cf8ca643ec7d3e3577ae49359ecb4e734c9d357ccd37559a5df0d31ebcf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bc12323fc530748326265497208a6034163a4cccacfc1a32d061459240860cb6
[INFO] running `Command { std: "docker" "start" "-a" "bc12323fc530748326265497208a6034163a4cccacfc1a32d061459240860cb6", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]     Checking rand_core v0.3.1
[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: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: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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `pack_2048` is imported redundantly
[INFO] [stdout]  --> tests/tests.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 1 | extern crate pack_2048;
[INFO] [stdout]   | ----------------------- the item `pack_2048` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 5 |     use pack_2048;
[INFO] [stdout]   |         ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.81s
[INFO] running `Command { std: "docker" "inspect" "bc12323fc530748326265497208a6034163a4cccacfc1a32d061459240860cb6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bc12323fc530748326265497208a6034163a4cccacfc1a32d061459240860cb6", kill_on_drop: false }`
[INFO] [stdout] bc12323fc530748326265497208a6034163a4cccacfc1a32d061459240860cb6