[INFO] updating cached repository https://github.com/joeldudley/obamas_head
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9ba104a08f8b0e116ccc183fe3af3239731e15a0
[INFO] checking joeldudley/obamas_head against try#85cc1486e1f000dce4bb8e1b3cfab2b654b102a8 for pr-73323
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjoeldudley%2Fobamas_head" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/joeldudley/obamas_head on toolchain 85cc1486e1f000dce4bb8e1b3cfab2b654b102a8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+85cc1486e1f000dce4bb8e1b3cfab2b654b102a8" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/joeldudley/obamas_head
[INFO] finished tweaking git repo https://github.com/joeldudley/obamas_head
[INFO] tweaked toml for git repo https://github.com/joeldudley/obamas_head written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/joeldudley/obamas_head already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+85cc1486e1f000dce4bb8e1b3cfab2b654b102a8" "fetch" "--locked" "--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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+85cc1486e1f000dce4bb8e1b3cfab2b654b102a8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7ed6484e77e5ac471b7b742b19176edf9f9174c7326f87332d1f006c8d7787ab
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "7ed6484e77e5ac471b7b742b19176edf9f9174c7326f87332d1f006c8d7787ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7ed6484e77e5ac471b7b742b19176edf9f9174c7326f87332d1f006c8d7787ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7ed6484e77e5ac471b7b742b19176edf9f9174c7326f87332d1f006c8d7787ab", kill_on_drop: false }`
[INFO] [stdout] 7ed6484e77e5ac471b7b742b19176edf9f9174c7326f87332d1f006c8d7787ab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+85cc1486e1f000dce4bb8e1b3cfab2b654b102a8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7829ed2e0be1477e966b1816a85bacce4fed12b9958832dbbde96e845898d839
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "7829ed2e0be1477e966b1816a85bacce4fed12b9958832dbbde96e845898d839", kill_on_drop: false }`
[INFO] [stderr]     Checking obamas_head v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `sender`
[INFO] [stdout]   --> src/main.rs:24:10
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let (sender, receiver): (Sender<bool>, Receiver<bool>) = mpsc::channel();
[INFO] [stdout]    |          ^^^^^^ help: if this is intentional, prefix it with an underscore: `_sender`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `receiver`
[INFO] [stdout]   --> src/main.rs:38:52
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn handle_incoming_requests(listener: TcpListener, receiver: Receiver<bool>) {
[INFO] [stdout]    |                                                    ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_receiver`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sender`
[INFO] [stdout]   --> src/main.rs:24:10
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let (sender, receiver): (Sender<bool>, Receiver<bool>) = mpsc::channel();
[INFO] [stdout]    |          ^^^^^^ help: if this is intentional, prefix it with an underscore: `_sender`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `receiver`
[INFO] [stdout]   --> src/main.rs:38:52
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn handle_incoming_requests(listener: TcpListener, receiver: Receiver<bool>) {
[INFO] [stdout]    |                                                    ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_receiver`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 28 |     listener_thread_handle.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/main.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 28 |     listener_thread_handle.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.65s
[INFO] running `Command { std: "docker" "inspect" "7829ed2e0be1477e966b1816a85bacce4fed12b9958832dbbde96e845898d839", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7829ed2e0be1477e966b1816a85bacce4fed12b9958832dbbde96e845898d839", kill_on_drop: false }`
[INFO] [stdout] 7829ed2e0be1477e966b1816a85bacce4fed12b9958832dbbde96e845898d839