[INFO] fetching crate veb-rs 0.1.1...
[INFO] checking veb-rs-0.1.1 against try#6f12b8fe67b4eed2e838dab803ed9493b9d62c0f for pr-79073
[INFO] extracting crate veb-rs 0.1.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate veb-rs 0.1.1 on toolchain 6f12b8fe67b4eed2e838dab803ed9493b9d62c0f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate veb-rs 0.1.1
[INFO] finished tweaking crates.io crate veb-rs 0.1.1
[INFO] tweaked toml for crates.io crate veb-rs 0.1.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded clippy v0.0.21
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dc14a39755f44d487af16ac8d2d8f955c6facff18308918b9a781c3c6d74ae63
[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" "dc14a39755f44d487af16ac8d2d8f955c6facff18308918b9a781c3c6d74ae63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dc14a39755f44d487af16ac8d2d8f955c6facff18308918b9a781c3c6d74ae63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dc14a39755f44d487af16ac8d2d8f955c6facff18308918b9a781c3c6d74ae63", kill_on_drop: false }`
[INFO] [stdout] dc14a39755f44d487af16ac8d2d8f955c6facff18308918b9a781c3c6d74ae63
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e9081a50b1a2c67899d63963c9d92e66ca10a7d9d6027a40dbe66d21168bf225
[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" "e9081a50b1a2c67899d63963c9d92e66ca10a7d9d6027a40dbe66d21168bf225", kill_on_drop: false }`
[INFO] [stderr]     Checking veb-rs v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:254:21
[INFO] [stdout]     |
[INFO] [stdout] 254 |                 let mut subtree = &mut self.children[idx as usize];
[INFO] [stdout]     |                     ----^^^^^^^
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:254:21
[INFO] [stdout]     |
[INFO] [stdout] 254 |                 let mut subtree = &mut self.children[idx as usize];
[INFO] [stdout]     |                     ----^^^^^^^
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:217:21
[INFO] [stdout]     |
[INFO] [stdout] 217 |                     mem::replace(subtree, Some(new_tree));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:217:21
[INFO] [stdout]     |
[INFO] [stdout] 217 |                     mem::replace(subtree, Some(new_tree));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.60s
[INFO] running `Command { std: "docker" "inspect" "e9081a50b1a2c67899d63963c9d92e66ca10a7d9d6027a40dbe66d21168bf225", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e9081a50b1a2c67899d63963c9d92e66ca10a7d9d6027a40dbe66d21168bf225", kill_on_drop: false }`
[INFO] [stdout] e9081a50b1a2c67899d63963c9d92e66ca10a7d9d6027a40dbe66d21168bf225