[INFO] updating cached repository https://github.com/yuu/rust-future-example
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] c5704fd681f1180c6d45ceaf720eccd7d1e0247b
[INFO] checking yuu/rust-future-example against master#2748a9fd93dd1a00a4521f4f16de5befbf77f6cd for pr-62262-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyuu%2Frust-future-example" "/workspace/builds/worker-7/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/yuu/rust-future-example on toolchain 2748a9fd93dd1a00a4521f4f16de5befbf77f6cd
[INFO] running `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/yuu/rust-future-example
[INFO] finished tweaking git repo https://github.com/yuu/rust-future-example
[INFO] tweaked toml for git repo https://github.com/yuu/rust-future-example written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/yuu/rust-future-example already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "MAP_USER_ID=0" "-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" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a8bb8dcf35f9f0f5d7ada1f0cd45bea47f4fc770d4d3a67e3e0bf81a23ffe0f5
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[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking async-util v0.1.0 (https://github.com/tokio-rs/async#e1b3ba3d)
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[INFO] [stderr] warning: unused import: `AsyncWriteExt`
[INFO] [stderr]  --> src/main.rs:4:31
[INFO] [stderr]   |
[INFO] [stderr] 4 | use tokio::io::{AsyncReadExt, AsyncWriteExt};
[INFO] [stderr]   |                               ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[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/main.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![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` that must be used
[INFO] [stderr]  --> src/main.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     stream.read_exact(&mut buf).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] warning: unused import: `AsyncWriteExt`
[INFO] [stderr]  --> src/main.rs:4:31
[INFO] [stderr]   |
[INFO] [stderr] 4 | use tokio::io::{AsyncReadExt, AsyncWriteExt};
[INFO] [stderr]   |                               ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[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/main.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![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` that must be used
[INFO] [stderr]  --> src/main.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     stream.read_exact(&mut buf).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 31.14s
[INFO] running `"docker" "inspect" "a8bb8dcf35f9f0f5d7ada1f0cd45bea47f4fc770d4d3a67e3e0bf81a23ffe0f5"`
[INFO] running `"docker" "rm" "-f" "a8bb8dcf35f9f0f5d7ada1f0cd45bea47f4fc770d4d3a67e3e0bf81a23ffe0f5"`
[INFO] [stdout] a8bb8dcf35f9f0f5d7ada1f0cd45bea47f4fc770d4d3a67e3e0bf81a23ffe0f5