[INFO] fetching crate workerpool 1.2.0...
[INFO] checking workerpool-1.2.0 against try#894d32a5432c6a6461bb2aac7c3d5f2e87dce83f for pr-77015
[INFO] extracting crate workerpool 1.2.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate workerpool 1.2.0 on toolchain 894d32a5432c6a6461bb2aac7c3d5f2e87dce83f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "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-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a8ab3b8a7ee67144301dc1a3fc92ba19dd31c7a2d495bae9622d1b5b9aa16ab
[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" "1a8ab3b8a7ee67144301dc1a3fc92ba19dd31c7a2d495bae9622d1b5b9aa16ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a8ab3b8a7ee67144301dc1a3fc92ba19dd31c7a2d495bae9622d1b5b9aa16ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a8ab3b8a7ee67144301dc1a3fc92ba19dd31c7a2d495bae9622d1b5b9aa16ab", kill_on_drop: false }`
[INFO] [stdout] 1a8ab3b8a7ee67144301dc1a3fc92ba19dd31c7a2d495bae9622d1b5b9aa16ab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f2d4bab6e319b642efbaacccc02bc3226a5d11237557561143b2b1bf244ea4cb
[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" "f2d4bab6e319b642efbaacccc02bc3226a5d11237557561143b2b1bf244ea4cb", kill_on_drop: false }`
[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]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]     Checking owning_ref v0.4.1
[INFO] [stderr]     Checking rand v0.6.5
[INFO] [stderr]     Checking lock_api v0.1.5
[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 5.97s
[INFO] running `Command { std: "docker" "inspect" "f2d4bab6e319b642efbaacccc02bc3226a5d11237557561143b2b1bf244ea4cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f2d4bab6e319b642efbaacccc02bc3226a5d11237557561143b2b1bf244ea4cb", kill_on_drop: false }`
[INFO] [stdout] f2d4bab6e319b642efbaacccc02bc3226a5d11237557561143b2b1bf244ea4cb