[INFO] fetching crate sonos_discovery 0.0.2...
[INFO] checking sonos_discovery-0.0.2 against try#c387b04bf028733cd561d62128c8a5eee4bc1458+rustflags=-Dtail_expr_drop_order for pr-130930
[INFO] extracting crate sonos_discovery 0.0.2 into /workspace/builds/worker-4-tc2/source
[INFO] validating manifest of crates.io crate sonos_discovery 0.0.2 on toolchain c387b04bf028733cd561d62128c8a5eee4bc1458
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate sonos_discovery 0.0.2
[INFO] finished tweaking crates.io crate sonos_discovery 0.0.2
[INFO] tweaked toml for crates.io crate sonos_discovery 0.0.2 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate crates.io crate sonos_discovery 0.0.2 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" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition while the latest is 2021
[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@sha256:6252d7ea7fb8caaf7af6d800c5fb250a9cd862b9a7f9508afb3c54fa7fe1102e" "/opt/rustwide/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6e5c35657cd2be5c826e9b8576ee6a59e1ad560640056484ddceecfdf08d08a5
[INFO] running `Command { std: "docker" "start" "-a" "6e5c35657cd2be5c826e9b8576ee6a59e1ad560640056484ddceecfdf08d08a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6e5c35657cd2be5c826e9b8576ee6a59e1ad560640056484ddceecfdf08d08a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e5c35657cd2be5c826e9b8576ee6a59e1ad560640056484ddceecfdf08d08a5", kill_on_drop: false }`
[INFO] [stdout] 6e5c35657cd2be5c826e9b8576ee6a59e1ad560640056484ddceecfdf08d08a5
[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 -Dtail_expr_drop_order" "-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@sha256:6252d7ea7fb8caaf7af6d800c5fb250a9cd862b9a7f9508afb3c54fa7fe1102e" "/opt/rustwide/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3bb25d7ad5ce182e89895f0e8e1bac0996abff2cc773962585c13ee1fc4b022e
[INFO] running `Command { std: "docker" "start" "-a" "3bb25d7ad5ce182e89895f0e8e1bac0996abff2cc773962585c13ee1fc4b022e", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition while the latest is 2021
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling num-traits v0.2.9
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-bigint v0.2.3
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]     Checking num v0.2.0
[INFO] [stderr]     Checking socket v0.0.7
[INFO] [stderr]     Checking sonos_discovery v0.0.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `Result::<T, E>::is_ok` that must be used
[INFO] [stdout]    --> src/lib.rs:122:25
[INFO] [stdout]     |
[INFO] [stdout] 122 |                         sender.send((_addr, _data)).is_ok();
[INFO] [stdout]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to assert that this is ok, consider `.unwrap()` instead
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 122 |                         let _ = sender.send((_addr, _data)).is_ok();
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Result::<T, E>::is_ok` that must be used
[INFO] [stdout]    --> src/lib.rs:122:25
[INFO] [stdout]     |
[INFO] [stdout] 122 |                         sender.send((_addr, _data)).is_ok();
[INFO] [stdout]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to assert that this is ok, consider `.unwrap()` instead
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 122 |                         let _ = sender.send((_addr, _data)).is_ok();
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.19s
[INFO] running `Command { std: "docker" "inspect" "3bb25d7ad5ce182e89895f0e8e1bac0996abff2cc773962585c13ee1fc4b022e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3bb25d7ad5ce182e89895f0e8e1bac0996abff2cc773962585c13ee1fc4b022e", kill_on_drop: false }`
[INFO] [stdout] 3bb25d7ad5ce182e89895f0e8e1bac0996abff2cc773962585c13ee1fc4b022e