[INFO] fetching crate tcpclient 1.3.1...
[INFO] testing tcpclient-1.3.1 against beta-2021-08-01 for beta-1.55-1
[INFO] extracting crate tcpclient 1.3.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate tcpclient 1.3.1 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tcpclient 1.3.1
[INFO] finished tweaking crates.io crate tcpclient 1.3.1
[INFO] tweaked toml for crates.io crate tcpclient 1.3.1 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ba7a71a819cf497ebd31fe2277cbf9146bf55cce277da1fbd281c0281ca41123
[INFO] running `Command { std: "docker" "start" "-a" "ba7a71a819cf497ebd31fe2277cbf9146bf55cce277da1fbd281c0281ca41123", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ba7a71a819cf497ebd31fe2277cbf9146bf55cce277da1fbd281c0281ca41123", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba7a71a819cf497ebd31fe2277cbf9146bf55cce277da1fbd281c0281ca41123", kill_on_drop: false }`
[INFO] [stdout] ba7a71a819cf497ebd31fe2277cbf9146bf55cce277da1fbd281c0281ca41123
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 671c524f5173b4f647af1a22dcb53df25742dc7f0c6e9ac65dedbee82056bccd
[INFO] running `Command { std: "docker" "start" "-a" "671c524f5173b4f647af1a22dcb53df25742dc7f0c6e9ac65dedbee82056bccd", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling pin-project-lite v0.2.7
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling async-trait v0.1.51
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling anyhow v1.0.42
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling cache-padded v1.1.1
[INFO] [stderr]    Compiling bytes v1.0.1
[INFO] [stderr]    Compiling futures-micro v0.5.0
[INFO] [stderr]    Compiling concurrent-queue v1.2.2
[INFO] [stderr]    Compiling async-oneshot v0.5.0
[INFO] [stderr]    Compiling tokio v1.9.0
[INFO] [stderr]    Compiling mio v0.7.13
[INFO] [stderr]    Compiling aqueue v1.1.3
[INFO] [stderr]    Compiling tcpclient v1.3.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(async_closure)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tcpclient` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "671c524f5173b4f647af1a22dcb53df25742dc7f0c6e9ac65dedbee82056bccd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "671c524f5173b4f647af1a22dcb53df25742dc7f0c6e9ac65dedbee82056bccd", kill_on_drop: false }`
[INFO] [stdout] 671c524f5173b4f647af1a22dcb53df25742dc7f0c6e9ac65dedbee82056bccd
