[INFO] fetching crate busbus 0.1.0...
[INFO] checking busbus-0.1.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate busbus 0.1.0 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate busbus 0.1.0 on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate busbus 0.1.0
[INFO] finished tweaking crates.io crate busbus 0.1.0
[INFO] tweaked toml for crates.io crate busbus 0.1.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 7 packages
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 117f058e5efd2ae4cbbd50c63e1c3666ef6abd56cb70ee4ad49e726c6dbac7ac
[INFO] running `Command { std: "docker" "start" "-a" "117f058e5efd2ae4cbbd50c63e1c3666ef6abd56cb70ee4ad49e726c6dbac7ac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "117f058e5efd2ae4cbbd50c63e1c3666ef6abd56cb70ee4ad49e726c6dbac7ac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "117f058e5efd2ae4cbbd50c63e1c3666ef6abd56cb70ee4ad49e726c6dbac7ac", kill_on_drop: false }`
[INFO] [stdout] 117f058e5efd2ae4cbbd50c63e1c3666ef6abd56cb70ee4ad49e726c6dbac7ac
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 261ff5a55782a9fa966f42c727c8d7425602cfd2be8d5a2ff0fc2b20f1d20c02
[INFO] running `Command { std: "docker" "start" "-a" "261ff5a55782a9fa966f42c727c8d7425602cfd2be8d5a2ff0fc2b20f1d20c02", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-utils v0.8.19
[INFO] [stderr]     Checking crossbeam-epoch v0.9.18
[INFO] [stderr]     Checking crossbeam-channel v0.5.12
[INFO] [stderr]     Checking crossbeam-queue v0.3.11
[INFO] [stderr]     Checking crossbeam-deque v0.8.5
[INFO] [stderr]     Checking crossbeam v0.8.4
[INFO] [stderr]     Checking busbus v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]  --> src/lib.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::error::Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]  --> src/lib.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::error::Error;
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.32s
[INFO] running `Command { std: "docker" "inspect" "261ff5a55782a9fa966f42c727c8d7425602cfd2be8d5a2ff0fc2b20f1d20c02", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "261ff5a55782a9fa966f42c727c8d7425602cfd2be8d5a2ff0fc2b20f1d20c02", kill_on_drop: false }`
[INFO] [stdout] 261ff5a55782a9fa966f42c727c8d7425602cfd2be8d5a2ff0fc2b20f1d20c02