[INFO] fetching crate cb_fut 0.2.1...
[INFO] checking cb_fut-0.2.1 against try#9c1dcf141bc0875407c4eb36972857bd3db713e2 for pr-81863
[INFO] extracting crate cb_fut 0.2.1 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate cb_fut 0.2.1 on toolchain 9c1dcf141bc0875407c4eb36972857bd3db713e2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cb_fut 0.2.1
[INFO] finished tweaking crates.io crate cb_fut 0.2.1
[INFO] tweaked toml for crates.io crate cb_fut 0.2.1 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "metadata" "--no-deps" "--format-version=1", 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] d30a4b013dbc5118834e8d23912d7df23ea0385994553544024864b95f2ad509
[INFO] running `Command { std: "docker" "start" "-a" "d30a4b013dbc5118834e8d23912d7df23ea0385994553544024864b95f2ad509", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d30a4b013dbc5118834e8d23912d7df23ea0385994553544024864b95f2ad509", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d30a4b013dbc5118834e8d23912d7df23ea0385994553544024864b95f2ad509", kill_on_drop: false }`
[INFO] [stdout] d30a4b013dbc5118834e8d23912d7df23ea0385994553544024864b95f2ad509
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ead173ed5d84f511681a978239149bf56a889df26c8112f946810c84e34faae9
[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" "ead173ed5d84f511681a978239149bf56a889df26c8112f946810c84e34faae9", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling libc v0.2.85
[INFO] [stderr]     Checking once_cell v1.5.2
[INFO] [stderr]     Checking pin-utils v0.1.0
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking pin-project-lite v0.2.4
[INFO] [stderr]    Compiling futures-macro v0.3.12
[INFO] [stderr]     Checking futures-task v0.3.12
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking futures-util v0.3.12
[INFO] [stderr]     Checking futures-executor v0.3.12
[INFO] [stderr]     Checking futures v0.3.12
[INFO] [stderr]     Checking cb_fut v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary braces around method argument
[INFO] [stdout]    --> src/lib.rs:666:71
[INFO] [stdout]     |
[INFO] [stdout] 666 |         futures::executor::block_on(once_blocked!(func(2 + 3, ->() -> {3i32})));
[INFO] [stdout]     |                                                                       ^^^^^^ help: remove these braces
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_braces)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary braces around method argument
[INFO] [stdout]    --> src/lib.rs:728:64
[INFO] [stdout]     |
[INFO] [stdout] 728 |         futures::executor::block_on(once_blocked!(func(->() -> {3i32}, 2 + 3)));
[INFO] [stdout]     |                                                                ^^^^^^ help: remove these braces
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `waker`
[INFO] [stdout]    --> src/lib.rs:400:5
[INFO] [stdout]     |
[INFO] [stdout] 400 |     waker: Option<futures::task::Waker>
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `waker`
[INFO] [stdout]    --> src/lib.rs:445:5
[INFO] [stdout]     |
[INFO] [stdout] 445 |     waker: Option<futures::task::Waker>
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `waker`
[INFO] [stdout]    --> src/lib.rs:400:5
[INFO] [stdout]     |
[INFO] [stdout] 400 |     waker: Option<futures::task::Waker>
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `waker`
[INFO] [stdout]    --> src/lib.rs:445:5
[INFO] [stdout]     |
[INFO] [stdout] 445 |     waker: Option<futures::task::Waker>
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 11.28s
[INFO] running `Command { std: "docker" "inspect" "ead173ed5d84f511681a978239149bf56a889df26c8112f946810c84e34faae9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ead173ed5d84f511681a978239149bf56a889df26c8112f946810c84e34faae9", kill_on_drop: false }`
[INFO] [stdout] ead173ed5d84f511681a978239149bf56a889df26c8112f946810c84e34faae9