[INFO] fetching crate convec 2.0.1...
[INFO] checking convec-2.0.1 against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] extracting crate convec 2.0.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate convec 2.0.1 on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate convec 2.0.1
[INFO] finished tweaking crates.io crate convec 2.0.1
[INFO] tweaked toml for crates.io crate convec 2.0.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fefec4c08af4c7dcfd9f6fcfafd08b423457551eb486556a2f2b58c04abd6061
[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" "fefec4c08af4c7dcfd9f6fcfafd08b423457551eb486556a2f2b58c04abd6061", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fefec4c08af4c7dcfd9f6fcfafd08b423457551eb486556a2f2b58c04abd6061", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fefec4c08af4c7dcfd9f6fcfafd08b423457551eb486556a2f2b58c04abd6061", kill_on_drop: false }`
[INFO] [stdout] fefec4c08af4c7dcfd9f6fcfafd08b423457551eb486556a2f2b58c04abd6061
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 417175fd4280d2f6190158e9ca54443f7f160042b710652212fc902e0c726941
[INFO] running `Command { std: "docker" "start" "-a" "417175fd4280d2f6190158e9ca54443f7f160042b710652212fc902e0c726941", kill_on_drop: false }`
[INFO] [stderr]     Checking owning_ref v0.3.3
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking parking_lot_core v0.2.14
[INFO] [stderr]     Checking parking_lot v0.4.8
[INFO] [stderr]     Checking convec v2.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `Option::<T>::is_some` that must be used
[INFO] [stdout]    --> src/lib.rs:176:21
[INFO] [stdout]     |
[INFO] [stdout] 176 |                     stack.pop().is_some();
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you intended to assert that this has a value, consider `.unwrap()` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.55s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "417175fd4280d2f6190158e9ca54443f7f160042b710652212fc902e0c726941", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "417175fd4280d2f6190158e9ca54443f7f160042b710652212fc902e0c726941", kill_on_drop: false }`
[INFO] [stdout] 417175fd4280d2f6190158e9ca54443f7f160042b710652212fc902e0c726941