[INFO] cloning repository https://github.com/JettTech/rust-async-workshop [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/JettTech/rust-async-workshop" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJettTech%2Frust-async-workshop", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJettTech%2Frust-async-workshop'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 81ee361f04c4fe1a3b7a0a1eb644a2f1a2cb1fc0 [INFO] testing JettTech/rust-async-workshop against 1.55.0 for beta-1.56-1 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJettTech%2Frust-async-workshop" "/workspace/builds/worker-7/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/JettTech/rust-async-workshop on toolchain 1.55.0 [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] removed /workspace/builds/worker-7/source/.cargo/config [INFO] removed /workspace/builds/worker-7/source/rust-toolchain [INFO] started tweaking git repo https://github.com/JettTech/rust-async-workshop [INFO] finished tweaking git repo https://github.com/JettTech/rust-async-workshop [INFO] tweaked toml for git repo https://github.com/JettTech/rust-async-workshop written to /workspace/builds/worker-7/source/Cargo.toml [INFO] crate git repo https://github.com/JettTech/rust-async-workshop already has a lockfile, it will not be regenerated [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "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" "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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 5b686b52c8f096a3ea1cb1796bb62fc4091812a1351a646528aa62abb3c051ed [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" "5b686b52c8f096a3ea1cb1796bb62fc4091812a1351a646528aa62abb3c051ed", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "5b686b52c8f096a3ea1cb1796bb62fc4091812a1351a646528aa62abb3c051ed", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "5b686b52c8f096a3ea1cb1796bb62fc4091812a1351a646528aa62abb3c051ed", kill_on_drop: false }` [INFO] [stdout] 5b686b52c8f096a3ea1cb1796bb62fc4091812a1351a646528aa62abb3c051ed [INFO] running `Command { std: "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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap. [INFO] [stdout] b21eaae910395fc7f69cdfb389450303c39d8196edd7d228a0240dc6464c3d70 [INFO] running `Command { std: "docker" "start" "-a" "b21eaae910395fc7f69cdfb389450303c39d8196edd7d228a0240dc6464c3d70", kill_on_drop: false }` [INFO] [stderr] Compiling syn v1.0.5 [INFO] [stderr] Compiling futures-core-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling arrayvec v0.4.11 [INFO] [stderr] Compiling futures-io-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling pin-project-internal v0.4.0-alpha.11 [INFO] [stderr] Compiling regex-syntax v0.6.12 [INFO] [stderr] Compiling tokio-sync v0.1.6 [INFO] [stderr] Compiling crossbeam-utils v0.6.6 [INFO] [stderr] Compiling tracing-core v0.1.6 [INFO] [stderr] Compiling num_cpus v1.10.1 [INFO] [stderr] Compiling net2 v0.2.33 [INFO] [stderr] Compiling memoffset v0.5.1 [INFO] [stderr] Compiling clap v2.33.0 [INFO] [stderr] Compiling tokio-io v0.1.12 [INFO] [stderr] Compiling parking_lot_core v0.6.2 [INFO] [stderr] Compiling parking_lot_core v0.4.0 [INFO] [stderr] Compiling futures-sink-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling mio v0.6.19 [INFO] [stderr] Compiling crossbeam-queue v0.1.2 [INFO] [stderr] Compiling tokio-executor v0.1.8 [INFO] [stderr] Compiling crossbeam-channel v0.3.9 [INFO] [stderr] Compiling futures-channel-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling parking_lot v0.9.0 [INFO] [stderr] Compiling parking_lot v0.7.1 [INFO] [stderr] Compiling tracing-log v0.1.0 [INFO] [stderr] Compiling tokio-codec v0.1.1 [INFO] [stderr] Compiling tokio-timer v0.2.11 [INFO] [stderr] Compiling tokio-current-thread v0.1.6 [INFO] [stderr] Compiling futures-util-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling crossbeam-epoch v0.7.2 [INFO] [stderr] Compiling mio-uds v0.6.7 [INFO] [stderr] Compiling tokio-reactor v0.1.9 [INFO] [stderr] Compiling crossbeam-deque v0.7.1 [INFO] [stderr] Compiling tokio-udp v0.1.5 [INFO] [stderr] Compiling tokio-uds v0.2.5 [INFO] [stderr] Compiling tokio-tcp v0.1.3 [INFO] [stderr] Compiling tokio-threadpool v0.1.15 [INFO] [stderr] Compiling regex-automata v0.1.8 [INFO] [stderr] Compiling regex v1.3.1 [INFO] [stderr] Compiling tokio-fs v0.1.6 [INFO] [stderr] Compiling tokio-sync v0.2.0-alpha.5 [INFO] [stderr] Compiling futures-executor-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling tokio v0.1.22 [INFO] [stderr] Compiling matchers v0.0.1 [INFO] [stderr] Compiling futures-preview v0.3.0-alpha.18 [INFO] [stderr] Compiling tracing-subscriber v0.1.3 [INFO] [stderr] Compiling proc-macro-error v0.2.6 [INFO] [stderr] Compiling tracing-attributes v0.1.3 [INFO] [stderr] Compiling tokio-macros v0.2.0-alpha.5 [INFO] [stderr] Compiling structopt-derive v0.3.2 [INFO] [stderr] Compiling tracing v0.1.9 [INFO] [stderr] Compiling tokio-executor v0.2.0-alpha.5 [INFO] [stderr] Compiling pin-project v0.4.0-alpha.11 [INFO] [stderr] Compiling tokio-io v0.2.0-alpha.5 [INFO] [stderr] Compiling structopt v0.3.2 [INFO] [stderr] Compiling tokio-codec v0.2.0-alpha.5 [INFO] [stderr] Compiling tokio-timer v0.3.0-alpha.5 [INFO] [stderr] Compiling tokio-fs v0.2.0-alpha.5 [INFO] [stderr] Compiling tokio-net v0.2.0-alpha.5 [INFO] [stderr] Compiling tokio v0.2.0-alpha.5 [INFO] [stderr] Compiling tracing-futures v0.0.1-alpha.2 (https://github.com/tokio-rs/tracing?rev=9f1126a00d105ff85f5b65fc6457699430b1bed4#9f1126a0) [INFO] [stderr] Compiling client v0.0.0 (/opt/rustwide/workdir/client) [INFO] [stderr] Compiling server v0.0.0 (/opt/rustwide/workdir/server) [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> client/src/../solutions/client.rs:10:39 [INFO] [stdout] | [INFO] [stdout] 10 | pub async fn run_client(user: String, mut stream: TcpStream) -> Result<(), Error> { [INFO] [stdout] | ----^^^^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_mut)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0277]: the `?` operator can only be used in an async block that returns `Result` or `Option` (or another type that implements `FromResidual`) [INFO] [stdout] --> client/src/main.rs:31:48 [INFO] [stdout] | [INFO] [stdout] 25 | #[tokio::main] [INFO] [stdout] | -------------- this function should return `Result` or `Option` to accept `?` [INFO] [stdout] ... [INFO] [stdout] 31 | let conn = TcpStream::connect(server).await?; [INFO] [stdout] | ^ cannot use the `?` operator in an async block that returns `()` [INFO] [stdout] | [INFO] [stdout] = help: the trait `FromResidual>` is not implemented for `()` [INFO] [stdout] note: required by `from_residual` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0308]: mismatched types [INFO] [stdout] --> client/src/main.rs:25:1 [INFO] [stdout] | [INFO] [stdout] 25 | #[tokio::main] [INFO] [stdout] | ^^^^^^^^^^^^^^ [INFO] [stdout] | | [INFO] [stdout] | expected enum `Result`, found `()` [INFO] [stdout] | help: try using a variant of the expected enum: `Ok(#[tokio::main])` [INFO] [stdout] 26 | async fn main() -> Result<(), client::Error> { [INFO] [stdout] | ------------------------- expected `Result<(), Box<(dyn std::error::Error + 'static)>>` because of return type [INFO] [stdout] | [INFO] [stdout] = note: expected enum `Result<(), Box<(dyn std::error::Error + 'static)>>` [INFO] [stdout] found unit type `()` [INFO] [stdout] = note: this error originates in the attribute macro `tokio::main` (in Nightly builds, run with -Z macro-backtrace for more info) [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: aborting due to 2 previous errors; 1 warning emitted [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] Some errors have detailed explanations: E0277, E0308. [INFO] [stdout] [INFO] [stdout] For more information about an error, try `rustc --explain E0277`. [INFO] [stdout] [INFO] [stderr] error: could not compile `client` due to 3 previous errors; 1 warning emitted [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stderr] error: build failed [INFO] running `Command { std: "docker" "inspect" "b21eaae910395fc7f69cdfb389450303c39d8196edd7d228a0240dc6464c3d70", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "b21eaae910395fc7f69cdfb389450303c39d8196edd7d228a0240dc6464c3d70", kill_on_drop: false }` [INFO] [stdout] b21eaae910395fc7f69cdfb389450303c39d8196edd7d228a0240dc6464c3d70