[INFO] fetching crate convec 2.0.1...
[INFO] checking convec-2.0.1 against 1.55.0 for beta-1.56-3
[INFO] extracting crate convec 2.0.1 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate convec 2.0.1 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "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-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded smallvec v0.6.14
[INFO] [stderr]   Downloaded stable_deref_trait v1.2.0
[INFO] [stderr]   Downloaded parking_lot_core v0.2.14
[INFO] [stderr]   Downloaded parking_lot v0.4.8
[INFO] [stderr]   Downloaded owning_ref v0.3.3
[INFO] [stderr]   Downloaded rand v0.4.6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 373a5d393e925f53242278481c992276c5eb42190348731c3897fc51d5f68ce3
[INFO] running `Command { std: "docker" "start" "-a" "373a5d393e925f53242278481c992276c5eb42190348731c3897fc51d5f68ce3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "373a5d393e925f53242278481c992276c5eb42190348731c3897fc51d5f68ce3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "373a5d393e925f53242278481c992276c5eb42190348731c3897fc51d5f68ce3", kill_on_drop: false }`
[INFO] [stdout] 373a5d393e925f53242278481c992276c5eb42190348731c3897fc51d5f68ce3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e3e1765700b5f6a00d4fe180dcd150cdc78084fe515cae77abd231d051bedd4e
[INFO] running `Command { std: "docker" "start" "-a" "e3e1765700b5f6a00d4fe180dcd150cdc78084fe515cae77abd231d051bedd4e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]     Checking rand v0.4.6
[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 11.79s
[INFO] running `Command { std: "docker" "inspect" "e3e1765700b5f6a00d4fe180dcd150cdc78084fe515cae77abd231d051bedd4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e3e1765700b5f6a00d4fe180dcd150cdc78084fe515cae77abd231d051bedd4e", kill_on_drop: false }`
[INFO] [stdout] e3e1765700b5f6a00d4fe180dcd150cdc78084fe515cae77abd231d051bedd4e
