[INFO] fetching crate rconn 0.2.0...
[INFO] checking rconn-0.2.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate rconn 0.2.0 into /workspace/builds/worker-1-tc1/source
[INFO] validating manifest of crates.io crate rconn 0.2.0 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 rconn 0.2.0
[INFO] finished tweaking crates.io crate rconn 0.2.0
[INFO] tweaked toml for crates.io crate rconn 0.2.0 written to /workspace/builds/worker-1-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 17 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-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 1e6889b8ca6d060f48cb0174fed26b2d8a32cb84e76811b24e193d0e38db35c1
[INFO] running `Command { std: "docker" "start" "-a" "1e6889b8ca6d060f48cb0174fed26b2d8a32cb84e76811b24e193d0e38db35c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1e6889b8ca6d060f48cb0174fed26b2d8a32cb84e76811b24e193d0e38db35c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e6889b8ca6d060f48cb0174fed26b2d8a32cb84e76811b24e193d0e38db35c1", kill_on_drop: false }`
[INFO] [stdout] 1e6889b8ca6d060f48cb0174fed26b2d8a32cb84e76811b24e193d0e38db35c1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] ecd5f3cc476e0c1614fde9d018013ef17346397f8794d29d07123183a3449633
[INFO] running `Command { std: "docker" "start" "-a" "ecd5f3cc476e0c1614fde9d018013ef17346397f8794d29d07123183a3449633", kill_on_drop: false }`
[INFO] [stderr]     Checking serde v1.0.197
[INFO] [stderr]     Checking serde_json v1.0.115
[INFO] [stderr]     Checking rconn v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Arc` is imported redundantly
[INFO] [stdout]  --> src/server.rs:9:17
[INFO] [stdout]   |
[INFO] [stdout] 2 | use crate::conn::*;
[INFO] [stdout]   |     -------------- the item `Arc` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 9 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                 ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Mutex` is imported redundantly
[INFO] [stdout]  --> src/server.rs:9:22
[INFO] [stdout]   |
[INFO] [stdout] 2 | use crate::conn::*;
[INFO] [stdout]   |     -------------- the item `Mutex` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 9 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Arc` is imported redundantly
[INFO] [stdout]  --> src/server.rs:9:17
[INFO] [stdout]   |
[INFO] [stdout] 2 | use crate::conn::*;
[INFO] [stdout]   |     -------------- the item `Arc` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 9 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                 ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Mutex` is imported redundantly
[INFO] [stdout]  --> src/server.rs:9:22
[INFO] [stdout]   |
[INFO] [stdout] 2 | use crate::conn::*;
[INFO] [stdout]   |     -------------- the item `Mutex` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 9 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[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] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.46s
[INFO] running `Command { std: "docker" "inspect" "ecd5f3cc476e0c1614fde9d018013ef17346397f8794d29d07123183a3449633", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ecd5f3cc476e0c1614fde9d018013ef17346397f8794d29d07123183a3449633", kill_on_drop: false }`
[INFO] [stdout] ecd5f3cc476e0c1614fde9d018013ef17346397f8794d29d07123183a3449633