[INFO] fetching crate cb_fut 0.2.1...
[INFO] checking cb_fut-0.2.1 against master#fc81ad22c453776de16acf9938976930cf8c9401 for pr-77325
[INFO] extracting crate cb_fut 0.2.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate cb_fut 0.2.1 on toolchain fc81ad22c453776de16acf9938976930cf8c9401
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+fc81ad22c453776de16acf9938976930cf8c9401" "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-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+fc81ad22c453776de16acf9938976930cf8c9401" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+fc81ad22c453776de16acf9938976930cf8c9401" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+fc81ad22c453776de16acf9938976930cf8c9401" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 933d8717f0cdf3373bfcaed1fa713d16a469e36b166c41decf55c257a7351e52
[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" "933d8717f0cdf3373bfcaed1fa713d16a469e36b166c41decf55c257a7351e52", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "933d8717f0cdf3373bfcaed1fa713d16a469e36b166c41decf55c257a7351e52", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "933d8717f0cdf3373bfcaed1fa713d16a469e36b166c41decf55c257a7351e52", kill_on_drop: false }`
[INFO] [stdout] 933d8717f0cdf3373bfcaed1fa713d16a469e36b166c41decf55c257a7351e52
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+fc81ad22c453776de16acf9938976930cf8c9401" "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] 43f9e3948c2566e98b432c79ee0d3ae2a24ee7ec21ed03eb163493db4222410a
[INFO] running `Command { std: "docker" "start" "-a" "43f9e3948c2566e98b432c79ee0d3ae2a24ee7ec21ed03eb163493db4222410a", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]     Checking pin-utils v0.1.0
[INFO] [stderr]     Checking futures-io v0.3.15
[INFO] [stderr]    Compiling futures-macro v0.3.15
[INFO] [stderr]    Compiling futures-util v0.3.15
[INFO] [stderr]     Checking futures-executor v0.3.15
[INFO] [stderr]     Checking futures v0.3.15
[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 25.14s
[INFO] running `Command { std: "docker" "inspect" "43f9e3948c2566e98b432c79ee0d3ae2a24ee7ec21ed03eb163493db4222410a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43f9e3948c2566e98b432c79ee0d3ae2a24ee7ec21ed03eb163493db4222410a", kill_on_drop: false }`
[INFO] [stdout] 43f9e3948c2566e98b432c79ee0d3ae2a24ee7ec21ed03eb163493db4222410a