[INFO] fetching crate candid_server 0.3.0...
[INFO] checking candid_server-0.3.0 against try#07fecb9cf34c4979a772ba38c99d6d9144768413 for pr-87710
[INFO] extracting crate candid_server 0.3.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate candid_server 0.3.0 on toolchain 07fecb9cf34c4979a772ba38c99d6d9144768413
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate candid_server 0.3.0
[INFO] finished tweaking crates.io crate candid_server 0.3.0
[INFO] tweaked toml for crates.io crate candid_server 0.3.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cd23c5a33bdebe8b97d08354f47e92a0e0aafb03095dd9fbe29d99de13b40b0d
[INFO] running `Command { std: "docker" "start" "-a" "cd23c5a33bdebe8b97d08354f47e92a0e0aafb03095dd9fbe29d99de13b40b0d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cd23c5a33bdebe8b97d08354f47e92a0e0aafb03095dd9fbe29d99de13b40b0d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd23c5a33bdebe8b97d08354f47e92a0e0aafb03095dd9fbe29d99de13b40b0d", kill_on_drop: false }`
[INFO] [stdout] cd23c5a33bdebe8b97d08354f47e92a0e0aafb03095dd9fbe29d99de13b40b0d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 12198b121f68a74a21c4ee07ab2d021aaab3f7d48d628afc5faf5a7d8bb25dfe
[INFO] running `Command { std: "docker" "start" "-a" "12198b121f68a74a21c4ee07ab2d021aaab3f7d48d628afc5faf5a7d8bb25dfe", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.100
[INFO] [stderr]     Checking bitflags v0.4.0
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking hex v0.2.0
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking itertools v0.4.19
[INFO] [stderr]     Checking vec_map v0.8.2
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking try_from v0.2.2
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking nix v0.5.1
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking socketcan v1.7.0
[INFO] [stderr]     Checking candid_server v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/can_reader.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |         &self.clients.lock().unwrap().push(channel);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[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] 49 |         let _ = &self.clients.lock().unwrap().push(channel);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/can_reader.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |         &self.clients.lock().unwrap().push(channel);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[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] 49 |         let _ = &self.clients.lock().unwrap().push(channel);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.54s
[INFO] running `Command { std: "docker" "inspect" "12198b121f68a74a21c4ee07ab2d021aaab3f7d48d628afc5faf5a7d8bb25dfe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12198b121f68a74a21c4ee07ab2d021aaab3f7d48d628afc5faf5a7d8bb25dfe", kill_on_drop: false }`
[INFO] [stdout] 12198b121f68a74a21c4ee07ab2d021aaab3f7d48d628afc5faf5a7d8bb25dfe