[INFO] cloning repository https://github.com/sebasmagri/rust-concurrency-patterns
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sebasmagri/rust-concurrency-patterns" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsebasmagri%2Frust-concurrency-patterns", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsebasmagri%2Frust-concurrency-patterns'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c916fe831faec73a7fb5d652e91fa9da528d85c4
[INFO] checking sebasmagri/rust-concurrency-patterns against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsebasmagri%2Frust-concurrency-patterns" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sebasmagri/rust-concurrency-patterns 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 git repo https://github.com/sebasmagri/rust-concurrency-patterns
[INFO] finished tweaking git repo https://github.com/sebasmagri/rust-concurrency-patterns
[INFO] tweaked toml for git repo https://github.com/sebasmagri/rust-concurrency-patterns written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/sebasmagri/rust-concurrency-patterns 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" "+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] 46b314290640d944764ec2f0b075a225428aa916f300216cd4edca06edee5606
[INFO] running `Command { std: "docker" "start" "-a" "46b314290640d944764ec2f0b075a225428aa916f300216cd4edca06edee5606", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "46b314290640d944764ec2f0b075a225428aa916f300216cd4edca06edee5606", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "46b314290640d944764ec2f0b075a225428aa916f300216cd4edca06edee5606", kill_on_drop: false }`
[INFO] [stdout] 46b314290640d944764ec2f0b075a225428aa916f300216cd4edca06edee5606
[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] 2a06c5e8d0d826c6a5310ae4d2197f76380b2ff88a8a52131ff04ad2df05b8fa
[INFO] running `Command { std: "docker" "start" "-a" "2a06c5e8d0d826c6a5310ae4d2197f76380b2ff88a8a52131ff04ad2df05b8fa", kill_on_drop: false }`
[INFO] [stderr]     Checking concurrency-patterns v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> examples/04-fan-in.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 32 |     consumer(Arc::new(Mutex::new(rx))).join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let _ = consumer(Arc::new(Mutex::new(rx))).join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.25s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "2a06c5e8d0d826c6a5310ae4d2197f76380b2ff88a8a52131ff04ad2df05b8fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a06c5e8d0d826c6a5310ae4d2197f76380b2ff88a8a52131ff04ad2df05b8fa", kill_on_drop: false }`
[INFO] [stdout] 2a06c5e8d0d826c6a5310ae4d2197f76380b2ff88a8a52131ff04ad2df05b8fa
[INFO] checking sebasmagri/rust-concurrency-patterns against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsebasmagri%2Frust-concurrency-patterns" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sebasmagri/rust-concurrency-patterns on toolchain 645bb72776a6a56a1a8f52631a44bd082b2ba509
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/sebasmagri/rust-concurrency-patterns
[INFO] finished tweaking git repo https://github.com/sebasmagri/rust-concurrency-patterns
[INFO] tweaked toml for git repo https://github.com/sebasmagri/rust-concurrency-patterns written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/sebasmagri/rust-concurrency-patterns 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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 21ee0be95d0bc0f80b6061a8799fc3051359e9d620e036c64da048432032a39c
[INFO] running `Command { std: "docker" "start" "-a" "21ee0be95d0bc0f80b6061a8799fc3051359e9d620e036c64da048432032a39c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "21ee0be95d0bc0f80b6061a8799fc3051359e9d620e036c64da048432032a39c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21ee0be95d0bc0f80b6061a8799fc3051359e9d620e036c64da048432032a39c", kill_on_drop: false }`
[INFO] [stdout] 21ee0be95d0bc0f80b6061a8799fc3051359e9d620e036c64da048432032a39c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a9af1783cf3423acce469e2caaca07e8883714b456b194978dee90043d69b236
[INFO] running `Command { std: "docker" "start" "-a" "a9af1783cf3423acce469e2caaca07e8883714b456b194978dee90043d69b236", kill_on_drop: false }`
[INFO] [stderr]     Checking concurrency-patterns v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> examples/04-fan-in.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 32 |     consumer(Arc::new(Mutex::new(rx))).join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let _ = consumer(Arc::new(Mutex::new(rx))).join();
[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 0.29s
[INFO] running `Command { std: "docker" "inspect" "a9af1783cf3423acce469e2caaca07e8883714b456b194978dee90043d69b236", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a9af1783cf3423acce469e2caaca07e8883714b456b194978dee90043d69b236", kill_on_drop: false }`
[INFO] [stdout] a9af1783cf3423acce469e2caaca07e8883714b456b194978dee90043d69b236