[INFO] fetching crate excov 1.0.0...
[INFO] checking excov-1.0.0 against try#998b6603a58e47f42ccce7a67943234e96b6839e for pr-143170
[INFO] extracting crate excov 1.0.0 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate excov 1.0.0
[INFO] finished tweaking crates.io crate excov 1.0.0
[INFO] tweaked toml for crates.io crate excov 1.0.0 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate excov 1.0.0 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] crate crates.io crate excov 1.0.0 already has a lockfile, it will not be regenerated
[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-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 1b8d1be8c95c243318b4d7f3b6d2205cf85b06f2b32b36d45d4cc041f6ddd327
[INFO] running `Command { std: "docker" "start" "-a" "1b8d1be8c95c243318b4d7f3b6d2205cf85b06f2b32b36d45d4cc041f6ddd327", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1b8d1be8c95c243318b4d7f3b6d2205cf85b06f2b32b36d45d4cc041f6ddd327", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b8d1be8c95c243318b4d7f3b6d2205cf85b06f2b32b36d45d4cc041f6ddd327", kill_on_drop: false }`
[INFO] [stdout] 1b8d1be8c95c243318b4d7f3b6d2205cf85b06f2b32b36d45d4cc041f6ddd327
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] c5c9ac76a4899df01aa3f47f8cb7dd3a0ad93b66882ce30a84b74dac8db13cb8
[INFO] running `Command { std: "docker" "start" "-a" "c5c9ac76a4899df01aa3f47f8cb7dd3a0ad93b66882ce30a84b74dac8db13cb8", kill_on_drop: false }`
[INFO] [stderr]     Checking excov v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `array::<impl [T; N]>::map` that must be used
[INFO] [stdout]     --> src/lib.rs:986:9
[INFO] [stdout]      |
[INFO] [stdout] 986  | /         [
[INFO] [stdout] 987  | |             GridVal {
[INFO] [stdout] 988  | |                 row: 1,
[INFO] [stdout] 989  | |                 col: 6,
[INFO] [stdout] ...    |
[INFO] [stdout] 1108 | |         .map(|id| problem.add_constraint([id]));
[INFO] [stdout]      | |_______________________________________________^
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 986  |         let _ = [
[INFO] [stdout]      |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.15s
[INFO] running `Command { std: "docker" "inspect" "c5c9ac76a4899df01aa3f47f8cb7dd3a0ad93b66882ce30a84b74dac8db13cb8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c5c9ac76a4899df01aa3f47f8cb7dd3a0ad93b66882ce30a84b74dac8db13cb8", kill_on_drop: false }`
[INFO] [stdout] c5c9ac76a4899df01aa3f47f8cb7dd3a0ad93b66882ce30a84b74dac8db13cb8