[INFO] fetching crate rbtree 0.1.5...
[INFO] checking rbtree-0.1.5 against beta for pr-78714
[INFO] extracting crate rbtree 0.1.5 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate rbtree 0.1.5 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rbtree 0.1.5
[INFO] finished tweaking crates.io crate rbtree 0.1.5
[INFO] tweaked toml for crates.io crate rbtree 0.1.5 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] acb9698a2ff816f576c62a86bbd2c31693a521a4e97e674d8b696d3b0fb2b68d
[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" "acb9698a2ff816f576c62a86bbd2c31693a521a4e97e674d8b696d3b0fb2b68d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "acb9698a2ff816f576c62a86bbd2c31693a521a4e97e674d8b696d3b0fb2b68d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acb9698a2ff816f576c62a86bbd2c31693a521a4e97e674d8b696d3b0fb2b68d", kill_on_drop: false }`
[INFO] [stdout] acb9698a2ff816f576c62a86bbd2c31693a521a4e97e674d8b696d3b0fb2b68d
[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" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 140bb2c8830942a5d3f66cd091f47cd5264934fa001e88bddff04bcae85a3f92
[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" "140bb2c8830942a5d3f66cd091f47cd5264934fa001e88bddff04bcae85a3f92", kill_on_drop: false }`
[INFO] [stderr]     Checking rbtree v0.1.5 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around type
[INFO] [stdout]    --> src/lib.rs:491:34
[INFO] [stdout]     |
[INFO] [stdout] 491 |     fn next(&mut self) -> Option<(&'a K)> {
[INFO] [stdout]     |                                  ^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around type
[INFO] [stdout]    --> src/lib.rs:535:34
[INFO] [stdout]     |
[INFO] [stdout] 535 |     fn next(&mut self) -> Option<(&'a V)> {
[INFO] [stdout]     |                                  ^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around type
[INFO] [stdout]    --> src/lib.rs:581:34
[INFO] [stdout]     |
[INFO] [stdout] 581 |     fn next(&mut self) -> Option<(&'a mut V)> {
[INFO] [stdout]     |                                  ^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::RBTree`
[INFO] [stdout]     --> src/lib.rs:1404:9
[INFO] [stdout]      |
[INFO] [stdout] 1404 |     use super::RBTree;
[INFO] [stdout]      |         ^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around type
[INFO] [stdout]    --> src/lib.rs:491:34
[INFO] [stdout]     |
[INFO] [stdout] 491 |     fn next(&mut self) -> Option<(&'a K)> {
[INFO] [stdout]     |                                  ^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around type
[INFO] [stdout]    --> src/lib.rs:535:34
[INFO] [stdout]     |
[INFO] [stdout] 535 |     fn next(&mut self) -> Option<(&'a V)> {
[INFO] [stdout]     |                                  ^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around type
[INFO] [stdout]    --> src/lib.rs:581:34
[INFO] [stdout]     |
[INFO] [stdout] 581 |     fn next(&mut self) -> Option<(&'a mut V)> {
[INFO] [stdout]     |                                  ^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.79s
[INFO] running `Command { std: "docker" "inspect" "140bb2c8830942a5d3f66cd091f47cd5264934fa001e88bddff04bcae85a3f92", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "140bb2c8830942a5d3f66cd091f47cd5264934fa001e88bddff04bcae85a3f92", kill_on_drop: false }`
[INFO] [stdout] 140bb2c8830942a5d3f66cd091f47cd5264934fa001e88bddff04bcae85a3f92