[INFO] fetching crate convec 2.0.1...
[INFO] checking convec-2.0.1 against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] extracting crate convec 2.0.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate convec 2.0.1 on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", 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-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded parking_lot_core v0.2.14
[INFO] [stderr]   Downloaded owning_ref v0.3.3
[INFO] [stderr]   Downloaded parking_lot v0.4.8
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 315baf1aaab710d6fa24cfcbd5d0997f9c010461cf8507cd0c3f667027d96c15
[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" "315baf1aaab710d6fa24cfcbd5d0997f9c010461cf8507cd0c3f667027d96c15", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "315baf1aaab710d6fa24cfcbd5d0997f9c010461cf8507cd0c3f667027d96c15", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "315baf1aaab710d6fa24cfcbd5d0997f9c010461cf8507cd0c3f667027d96c15", kill_on_drop: false }`
[INFO] [stdout] 315baf1aaab710d6fa24cfcbd5d0997f9c010461cf8507cd0c3f667027d96c15
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "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] 33a8d03e8516aa6c35d59d9895810763929571dd061c7e2a23748dedf29cf78a
[INFO] running `Command { std: "docker" "start" "-a" "33a8d03e8516aa6c35d59d9895810763929571dd061c7e2a23748dedf29cf78a", kill_on_drop: false }`
[INFO] [stderr]     Checking owning_ref v0.3.3
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.75s
[INFO] running `Command { std: "docker" "inspect" "33a8d03e8516aa6c35d59d9895810763929571dd061c7e2a23748dedf29cf78a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "33a8d03e8516aa6c35d59d9895810763929571dd061c7e2a23748dedf29cf78a", kill_on_drop: false }`
[INFO] [stdout] 33a8d03e8516aa6c35d59d9895810763929571dd061c7e2a23748dedf29cf78a