[INFO] fetching crate cb_fut 0.2.1...
[INFO] checking cb_fut-0.2.1 against try#353a0a223066e9f46a1d935f2271a26c3c5002bb for pr-75180
[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 353a0a223066e9f46a1d935f2271a26c3c5002bb
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "read-manifest" "--manifest-path" "Cargo.toml", 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" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "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" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "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-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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 572108c3c1c4c1e4c6abe71a8ee9e208d6f209416bfe81ee1c014723263b9d3d
[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" "572108c3c1c4c1e4c6abe71a8ee9e208d6f209416bfe81ee1c014723263b9d3d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "572108c3c1c4c1e4c6abe71a8ee9e208d6f209416bfe81ee1c014723263b9d3d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "572108c3c1c4c1e4c6abe71a8ee9e208d6f209416bfe81ee1c014723263b9d3d", kill_on_drop: false }`
[INFO] [stdout] 572108c3c1c4c1e4c6abe71a8ee9e208d6f209416bfe81ee1c014723263b9d3d
[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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+353a0a223066e9f46a1d935f2271a26c3c5002bb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 51e7468876e8866f2aca6b6dd0adc619f7c8c4b590e7a6ee6c2fe650279c50ba
[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" "51e7468876e8866f2aca6b6dd0adc619f7c8c4b590e7a6ee6c2fe650279c50ba", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling pin-project-internal v0.4.23
[INFO] [stderr]     Checking futures-core v0.3.5
[INFO] [stderr]     Checking once_cell v1.4.1
[INFO] [stderr]     Checking futures-io v0.3.5
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking futures-channel v0.3.5
[INFO] [stderr]     Checking futures-task v0.3.5
[INFO] [stderr]    Compiling futures-macro v0.3.5
[INFO] [stderr]     Checking pin-project v0.4.23
[INFO] [stderr]     Checking futures-util v0.3.5
[INFO] [stderr]     Checking futures-executor v0.3.5
[INFO] [stderr]     Checking futures v0.3.5
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 29.90s
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "51e7468876e8866f2aca6b6dd0adc619f7c8c4b590e7a6ee6c2fe650279c50ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51e7468876e8866f2aca6b6dd0adc619f7c8c4b590e7a6ee6c2fe650279c50ba", kill_on_drop: false }`
[INFO] [stdout] 51e7468876e8866f2aca6b6dd0adc619f7c8c4b590e7a6ee6c2fe650279c50ba