[INFO] fetching crate ixlist 0.1.0...
[INFO] checking ixlist-0.1.0 against beta for pr-78714
[INFO] extracting crate ixlist 0.1.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate ixlist 0.1.0 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 ixlist 0.1.0
[INFO] finished tweaking crates.io crate ixlist 0.1.0
[INFO] tweaked toml for crates.io crate ixlist 0.1.0 written to /workspace/builds/worker-0/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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 28c86f86067c959036991e5454ee3fd830cc86e9da527f78419a3f3a7f414ebd
[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" "28c86f86067c959036991e5454ee3fd830cc86e9da527f78419a3f3a7f414ebd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "28c86f86067c959036991e5454ee3fd830cc86e9da527f78419a3f3a7f414ebd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28c86f86067c959036991e5454ee3fd830cc86e9da527f78419a3f3a7f414ebd", kill_on_drop: false }`
[INFO] [stdout] 28c86f86067c959036991e5454ee3fd830cc86e9da527f78419a3f3a7f414ebd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 9fc332f3c9a66655dbb4dc06c5021bf18987680bb93605fa0c566e358b21bbd2
[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" "9fc332f3c9a66655dbb4dc06c5021bf18987680bb93605fa0c566e358b21bbd2", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking ixlist v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking itertools v0.6.5
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]   --> benches/bench1.rs:26:18
[INFO] [stdout]    |
[INFO] [stdout] 26 |         for _ in (0..n) {
[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 `for` iterator expression
[INFO] [stdout]   --> benches/bench1.rs:38:18
[INFO] [stdout]    |
[INFO] [stdout] 38 |         for _ in (0..n) {
[INFO] [stdout]    |                  ^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]   --> benches/bench1.rs:66:18
[INFO] [stdout]    |
[INFO] [stdout] 66 |         for _ in (0..n) {
[INFO] [stdout]    |                  ^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]   --> benches/bench1.rs:78:18
[INFO] [stdout]    |
[INFO] [stdout] 78 |         for _ in (0..n) {
[INFO] [stdout]    |                  ^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]   --> benches/bench1.rs:90:14
[INFO] [stdout]    |
[INFO] [stdout] 90 |     for _ in (0..n) {
[INFO] [stdout]    |              ^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> benches/bench1.rs:110:14
[INFO] [stdout]     |
[INFO] [stdout] 110 |     for _ in (0..n) {
[INFO] [stdout]     |              ^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `for` iterator expression
[INFO] [stdout]    --> benches/bench1.rs:131:14
[INFO] [stdout]     |
[INFO] [stdout] 131 |     for _ in (0..n) {
[INFO] [stdout]     |              ^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.03s
[INFO] running `Command { std: "docker" "inspect" "9fc332f3c9a66655dbb4dc06c5021bf18987680bb93605fa0c566e358b21bbd2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9fc332f3c9a66655dbb4dc06c5021bf18987680bb93605fa0c566e358b21bbd2", kill_on_drop: false }`
[INFO] [stdout] 9fc332f3c9a66655dbb4dc06c5021bf18987680bb93605fa0c566e358b21bbd2