[INFO] fetching crate workerpool 1.2.0...
[INFO] checking workerpool-1.2.0 against master#da897dfb6daa268a965d2d73620316ba56020a19 for pr-76219
[INFO] extracting crate workerpool 1.2.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate workerpool 1.2.0 on toolchain da897dfb6daa268a965d2d73620316ba56020a19
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+da897dfb6daa268a965d2d73620316ba56020a19" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate workerpool 1.2.0
[INFO] finished tweaking crates.io crate workerpool 1.2.0
[INFO] tweaked toml for crates.io crate workerpool 1.2.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+da897dfb6daa268a965d2d73620316ba56020a19" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+da897dfb6daa268a965d2d73620316ba56020a19" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+da897dfb6daa268a965d2d73620316ba56020a19" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cc0a0ec148b6e6a8fdbac59e08b4d37bd616928efb03cd4f7c386146c752292f
[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" "cc0a0ec148b6e6a8fdbac59e08b4d37bd616928efb03cd4f7c386146c752292f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cc0a0ec148b6e6a8fdbac59e08b4d37bd616928efb03cd4f7c386146c752292f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cc0a0ec148b6e6a8fdbac59e08b4d37bd616928efb03cd4f7c386146c752292f", kill_on_drop: false }`
[INFO] [stdout] cc0a0ec148b6e6a8fdbac59e08b4d37bd616928efb03cd4f7c386146c752292f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+da897dfb6daa268a965d2d73620316ba56020a19" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 73a4e8a069154a363ac2037651626cf591aa60ddb0bba385e24872bf65fcb374
[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" "73a4e8a069154a363ac2037651626cf591aa60ddb0bba385e24872bf65fcb374", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking owning_ref v0.4.1
[INFO] [stderr]     Checking lock_api v0.1.5
[INFO] [stderr]     Checking rand v0.6.5
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking smallvec v0.6.13
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]     Checking parking_lot v0.7.1
[INFO] [stderr]     Checking workerpool v1.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]     --> src/lib.rs:1023:33
[INFO] [stdout]      |
[INFO] [stdout] 1023 |     pub struct Thunk<'a, T>(Box<FnBox<Out = T> + Send + 'a>);
[INFO] [stdout]      |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn FnBox<Out = T> + Send + 'a`
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]     --> src/lib.rs:1023:33
[INFO] [stdout]      |
[INFO] [stdout] 1023 |     pub struct Thunk<'a, T>(Box<FnBox<Out = T> + Send + 'a>);
[INFO] [stdout]      |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn FnBox<Out = T> + Send + 'a`
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::result::Result::<T, E>::is_ok` that must be used
[INFO] [stdout]     --> src/lib.rs:1205:17
[INFO] [stdout]      |
[INFO] [stdout] 1205 |                 tx.send(1).is_ok();
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]      = note: if you intended to assert that this is ok, consider `.unwrap()` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.80s
[INFO] running `Command { std: "docker" "inspect" "73a4e8a069154a363ac2037651626cf591aa60ddb0bba385e24872bf65fcb374", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "73a4e8a069154a363ac2037651626cf591aa60ddb0bba385e24872bf65fcb374", kill_on_drop: false }`
[INFO] [stdout] 73a4e8a069154a363ac2037651626cf591aa60ddb0bba385e24872bf65fcb374