[INFO] crate async-ringbuffer 0.5.1 is already in cache
[INFO] checking async-ringbuffer-0.5.1 against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] extracting crate async-ringbuffer 0.5.1 into work/builds/worker-1/source
[INFO] validating manifest of crates.io crate async-ringbuffer 0.5.1 on toolchain c9edc02e8320a9e5799d185910ece7d491f524e6-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate async-ringbuffer 0.5.1
[INFO] finished tweaking crates.io crate async-ringbuffer 0.5.1
[INFO] tweaked toml for crates.io crate async-ringbuffer 0.5.1 written to work/builds/worker-1/source/Cargo.toml
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-1/source:/opt/rustwide/workdir:ro,Z" "-v" "/mnt/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] e2778203415e8f45cea01b696c5463c76fb32c2b34fb037d21d8d59e1dcc3dc3
[INFO] running `"docker" "start" "-a" "e2778203415e8f45cea01b696c5463c76fb32c2b34fb037d21d8d59e1dcc3dc3"`
[INFO] [stderr]     Checking async-ringbuffer v0.5.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stderr] warning: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stderr]  --> src/lib.rs:4:12
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(async_await)]
[INFO] [stderr]   |            ^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(stable_features)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.18
[INFO] [stderr] warning: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stderr]  --> src/lib.rs:4:12
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(async_await)]
[INFO] [stderr]   |            ^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(stable_features)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` in tuple element 1 that must be used
[INFO] [stderr]    --> src/lib.rs:280:9
[INFO] [stderr]     |
[INFO] [stderr] 280 |         block_on(async { join(write_all, read_all).await });
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 9.33s
[INFO] running `"docker" "inspect" "e2778203415e8f45cea01b696c5463c76fb32c2b34fb037d21d8d59e1dcc3dc3"`
[INFO] running `"docker" "rm" "-f" "e2778203415e8f45cea01b696c5463c76fb32c2b34fb037d21d8d59e1dcc3dc3"`
[INFO] [stdout] e2778203415e8f45cea01b696c5463c76fb32c2b34fb037d21d8d59e1dcc3dc3