[INFO] fetching crate cb_fut 0.2.1...
[INFO] checking cb_fut-0.2.1 against master#f82664191d0e8764b7435b9d72eb0e366b8b1464 for pr-83354
[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 f82664191d0e8764b7435b9d72eb0e366b8b1464
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "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" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "fetch" "--locked" "--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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] af4a876ede88bac9ba0dec7fef57a6b1572e83eb3c5f3abacdf13a7a684880ab
[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" "af4a876ede88bac9ba0dec7fef57a6b1572e83eb3c5f3abacdf13a7a684880ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af4a876ede88bac9ba0dec7fef57a6b1572e83eb3c5f3abacdf13a7a684880ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af4a876ede88bac9ba0dec7fef57a6b1572e83eb3c5f3abacdf13a7a684880ab", kill_on_drop: false }`
[INFO] [stdout] af4a876ede88bac9ba0dec7fef57a6b1572e83eb3c5f3abacdf13a7a684880ab
[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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 052c1b21017b6c51ae08be17a125e459c2fd4a7daf86b0ceb39c13f79ecc7439
[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" "052c1b21017b6c51ae08be17a125e459c2fd4a7daf86b0ceb39c13f79ecc7439", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling syn v1.0.65
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling libc v0.2.91
[INFO] [stderr]     Checking futures-core v0.3.13
[INFO] [stderr]     Checking futures-sink v0.3.13
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking futures-task v0.3.13
[INFO] [stderr]     Checking futures-io v0.3.13
[INFO] [stderr]     Checking pin-project-lite v0.2.6
[INFO] [stderr]     Checking pin-utils v0.1.0
[INFO] [stderr]     Checking futures-channel v0.3.13
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]    Compiling futures-macro v0.3.13
[INFO] [stderr]     Checking futures-util v0.3.13
[INFO] [stderr]     Checking futures-executor v0.3.13
[INFO] [stderr]     Checking futures v0.3.13
[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 27.07s
[INFO] running `Command { std: "docker" "inspect" "052c1b21017b6c51ae08be17a125e459c2fd4a7daf86b0ceb39c13f79ecc7439", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "052c1b21017b6c51ae08be17a125e459c2fd4a7daf86b0ceb39c13f79ecc7439", kill_on_drop: false }`
[INFO] [stdout] 052c1b21017b6c51ae08be17a125e459c2fd4a7daf86b0ceb39c13f79ecc7439