[INFO] updating cached repository https://github.com/daogangtang/learn-tokio
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/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] 98b13be0e474ffb1b6a4f84b3e9caa91d100296a
[INFO] checking daogangtang/learn-tokio against try#e689e5eaefe96e6dc3ed5bb629c521b7d207aff7 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdaogangtang%2Flearn-tokio" "work/builds/worker-4/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/daogangtang/learn-tokio on toolchain e689e5eaefe96e6dc3ed5bb629c521b7d207aff7-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+e689e5eaefe96e6dc3ed5bb629c521b7d207aff7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/daogangtang/learn-tokio
[INFO] finished tweaking git repo https://github.com/daogangtang/learn-tokio
[INFO] tweaked toml for git repo https://github.com/daogangtang/learn-tokio written to work/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/daogangtang/learn-tokio already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+e689e5eaefe96e6dc3ed5bb629c521b7d207aff7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-4/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" "+e689e5eaefe96e6dc3ed5bb629c521b7d207aff7-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] fa4146411bcbc2952e501a4f2bba328a28a067441f7238e1ff6c9f3f80984b08
[INFO] running `"docker" "start" "-a" "fa4146411bcbc2952e501a4f2bba328a28a067441f7238e1ff6c9f3f80984b08"`
[INFO] [stderr]     Checking learn-tokio0 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `tokio::io`
[INFO] [stderr]  --> src/tcp_server.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tokio::io;
[INFO] [stderr]   |     ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `tokio::prelude`
[INFO] [stderr]  --> src/tcp_server.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use tokio::prelude::*;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `e`
[INFO] [stderr]   --> src/tcp_server.rs:37:31
[INFO] [stderr]    |
[INFO] [stderr] 37 |                     .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, "oh no!"))
[INFO] [stderr]    |                               ^ help: consider prefixing with an underscore: `_e`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `futures::try_ready`
[INFO] [stderr]  --> src/concurrent_send_recv2.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use futures::try_ready;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `tokio::io`
[INFO] [stderr]  --> src/tcp_server.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use tokio::io;
[INFO] [stderr]   |     ^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `tokio::prelude`
[INFO] [stderr]  --> src/tcp_server.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use tokio::prelude::*;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `e`
[INFO] [stderr]   --> src/tcp_server.rs:37:31
[INFO] [stderr]    |
[INFO] [stderr] 37 |                     .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, "oh no!"))
[INFO] [stderr]    |                               ^ help: consider prefixing with an underscore: `_e`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `stdout`
[INFO] [stderr]   --> src/tcp_client.rs:12:13
[INFO] [stderr]    |
[INFO] [stderr] 12 |     let mut stdout = io::stdout();
[INFO] [stderr]    |             ^^^^^^ help: consider prefixing with an underscore: `_stdout`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/tcp_client.rs:12:9
[INFO] [stderr]    |
[INFO] [stderr] 12 |     let mut stdout = io::stdout();
[INFO] [stderr]    |         ----^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `futures::try_ready`
[INFO] [stderr]  --> src/concurrent_send_recv2.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use futures::try_ready;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `stdout`
[INFO] [stderr]   --> src/tcp_client.rs:12:13
[INFO] [stderr]    |
[INFO] [stderr] 12 |     let mut stdout = io::stdout();
[INFO] [stderr]    |             ^^^^^^ help: consider prefixing with an underscore: `_stdout`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/tcp_client.rs:12:9
[INFO] [stderr]    |
[INFO] [stderr] 12 |     let mut stdout = io::stdout();
[INFO] [stderr]    |         ----^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `futures::try_ready`
[INFO] [stderr]  --> src/concurrent_send_recv.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use futures::try_ready;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `e`
[INFO] [stderr]   --> src/tcp_server3.rs:29:31
[INFO] [stderr]    |
[INFO] [stderr] 29 |                     .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, "oh no!"))
[INFO] [stderr]    |                               ^ help: consider prefixing with an underscore: `_e`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `futures::try_ready`
[INFO] [stderr]  --> src/concurrent_send_recv.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use futures::try_ready;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `e`
[INFO] [stderr]   --> src/tcp_server3.rs:29:31
[INFO] [stderr]    |
[INFO] [stderr] 29 |                     .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, "oh no!"))
[INFO] [stderr]    |                               ^ help: consider prefixing with an underscore: `_e`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 58.81s
[INFO] running `"docker" "inspect" "fa4146411bcbc2952e501a4f2bba328a28a067441f7238e1ff6c9f3f80984b08"`
[INFO] running `"docker" "rm" "-f" "fa4146411bcbc2952e501a4f2bba328a28a067441f7238e1ff6c9f3f80984b08"`
[INFO] [stdout] fa4146411bcbc2952e501a4f2bba328a28a067441f7238e1ff6c9f3f80984b08