[INFO] cloning repository https://github.com/oleh-nats/signal_slot
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/oleh-nats/signal_slot" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Foleh-nats%2Fsignal_slot", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Foleh-nats%2Fsignal_slot'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b598852ffde220f0bc4f45a56886bee4543e09dc
[INFO] checking oleh-nats/signal_slot against master#c720f49c46ec3e70bbc2bbb3e0dd1fe7fc0a47f2 for pr-142712
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Foleh-nats%2Fsignal_slot" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/oleh-nats/signal_slot
[INFO] finished tweaking git repo https://github.com/oleh-nats/signal_slot
[INFO] tweaked toml for git repo https://github.com/oleh-nats/signal_slot written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/oleh-nats/signal_slot on toolchain c720f49c46ec3e70bbc2bbb3e0dd1fe7fc0a47f2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c720f49c46ec3e70bbc2bbb3e0dd1fe7fc0a47f2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/oleh-nats/signal_slot 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" "+c720f49c46ec3e70bbc2bbb3e0dd1fe7fc0a47f2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+c720f49c46ec3e70bbc2bbb3e0dd1fe7fc0a47f2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8750f197d7d8c9511394c9535870b44b6ef9be25d92329426d69dbf9cf3f8f4a
[INFO] running `Command { std: "docker" "start" "-a" "8750f197d7d8c9511394c9535870b44b6ef9be25d92329426d69dbf9cf3f8f4a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8750f197d7d8c9511394c9535870b44b6ef9be25d92329426d69dbf9cf3f8f4a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8750f197d7d8c9511394c9535870b44b6ef9be25d92329426d69dbf9cf3f8f4a", kill_on_drop: false }`
[INFO] [stdout] 8750f197d7d8c9511394c9535870b44b6ef9be25d92329426d69dbf9cf3f8f4a
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+c720f49c46ec3e70bbc2bbb3e0dd1fe7fc0a47f2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 68fadf12d20175a95a3ac2bf765648b58d18b7e6d637bdfadcf91524788fd689
[INFO] running `Command { std: "docker" "start" "-a" "68fadf12d20175a95a3ac2bf765648b58d18b7e6d637bdfadcf91524788fd689", kill_on_drop: false }`
[INFO] [stderr]     Checking signal_slot v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]   --> src/main.rs:28:13
[INFO] [stdout]    |
[INFO] [stdout] 28 |             self.observers.remove(index);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: closures are lazy and do nothing unless called
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused boxed `FnMut` trait object that must be used
[INFO] [stdout]   --> src/main.rs:28:13
[INFO] [stdout]    |
[INFO] [stdout] 28 |             self.observers.remove(index);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: closures are lazy and do nothing unless called
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.10s
[INFO] running `Command { std: "docker" "inspect" "68fadf12d20175a95a3ac2bf765648b58d18b7e6d637bdfadcf91524788fd689", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "68fadf12d20175a95a3ac2bf765648b58d18b7e6d637bdfadcf91524788fd689", kill_on_drop: false }`
[INFO] [stdout] 68fadf12d20175a95a3ac2bf765648b58d18b7e6d637bdfadcf91524788fd689