[INFO] fetching crate romio 0.3.0-alpha.8...
[INFO] extracting crate romio 0.3.0-alpha.8 into work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/reg/romio/0.3.0-alpha.8
[INFO] extracting crate romio 0.3.0-alpha.8 into work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/reg/romio/0.3.0-alpha.8
[INFO] validating manifest of romio-0.3.0-alpha.8 on toolchain master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of romio-0.3.0-alpha.8 on toolchain try#8f81d0bf6baf07b92f1246696722485c4ca0b049
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing romio-0.3.0-alpha.8
[INFO] finished frobbing romio-0.3.0-alpha.8
[INFO] frobbed toml for romio-0.3.0-alpha.8 written to work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/reg/romio/0.3.0-alpha.8/Cargo.toml
[INFO] started frobbing romio-0.3.0-alpha.8
[INFO] finished frobbing romio-0.3.0-alpha.8
[INFO] frobbed toml for romio-0.3.0-alpha.8 written to work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/reg/romio/0.3.0-alpha.8/Cargo.toml
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking romio-0.3.0-alpha.8 against try#8f81d0bf6baf07b92f1246696722485c4ca0b049 for pr-62008
[INFO] running `"docker" "create" "-v" "/mnt/big/ec2-user/crater/work/local/target-dirs/pr-62008/worker-4/try#8f81d0bf6baf07b92f1246696722485c4ca0b049:/opt/crater/target:rw,Z" "-v" "/mnt/big/ec2-user/crater/work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/reg/romio/0.3.0-alpha.8:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] d0d55aca816ce2900d9446917a4cc226020950337ec00bbac0b253ce171e62fd
[INFO] running `"docker" "start" "-a" "d0d55aca816ce2900d9446917a4cc226020950337ec00bbac0b253ce171e62fd"`
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking async-datagram v2.2.0
[INFO] [stderr]     Checking async-ready v2.1.0
[INFO] [stderr]     Checking env_logger v0.6.2
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling proc-macro-hack v0.5.8
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking romio v0.3.0-alpha.8 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> examples/echo.rs:41:10
[INFO] [stderr]    |
[INFO] [stderr] 41 |     let (mut reader, mut writer) = stream.split();
[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: variable does not need to be mutable
[INFO] [stderr]   --> examples/shakespeare-client.rs:12:13
[INFO] [stderr]    |
[INFO] [stderr] 12 |         let mut stream = TcpStream::connect(&"127.0.0.1:7878".parse().unwrap()).await?;
[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]     Finished dev [unoptimized + debuginfo] target(s) in 16.64s
[INFO] running `"docker" "inspect" "d0d55aca816ce2900d9446917a4cc226020950337ec00bbac0b253ce171e62fd"`
[INFO] running `"docker" "rm" "-f" "d0d55aca816ce2900d9446917a4cc226020950337ec00bbac0b253ce171e62fd"`
[INFO] [stdout] d0d55aca816ce2900d9446917a4cc226020950337ec00bbac0b253ce171e62fd