[INFO] fetching crate tcpserver 1.5.2...
[INFO] testing tcpserver-1.5.2 against 1.54.0 for beta-1.55-1
[INFO] extracting crate tcpserver 1.5.2 into /workspace/builds/worker-81/source
[INFO] validating manifest of crates.io crate tcpserver 1.5.2 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tcpserver 1.5.2
[INFO] finished tweaking crates.io crate tcpserver 1.5.2
[INFO] tweaked toml for crates.io crate tcpserver 1.5.2 written to /workspace/builds/worker-81/source/Cargo.toml
[INFO] crate crates.io crate tcpserver 1.5.2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded futures-micro v0.5.0
[INFO] [stderr]   Downloaded async-oneshot v0.5.0
[INFO] [stderr]   Downloaded tokio-openssl v0.6.1
[INFO] [stderr]   Downloaded vcpkg v0.2.14
[INFO] [stderr]   Downloaded aqueue v1.1.3
[INFO] [stderr]   Downloaded tcpclient v1.2.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-81/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-81/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" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3291e00bde0a665790ab403c18bcf5ee0b616bac3a6e9dc5c5b09e7d31712f42
[INFO] running `Command { std: "docker" "start" "-a" "3291e00bde0a665790ab403c18bcf5ee0b616bac3a6e9dc5c5b09e7d31712f42", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3291e00bde0a665790ab403c18bcf5ee0b616bac3a6e9dc5c5b09e7d31712f42", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3291e00bde0a665790ab403c18bcf5ee0b616bac3a6e9dc5c5b09e7d31712f42", kill_on_drop: false }`
[INFO] [stdout] 3291e00bde0a665790ab403c18bcf5ee0b616bac3a6e9dc5c5b09e7d31712f42
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-81/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-81/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" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] acc7cd54be402887b80790ba897a70593dcc57ac80287f82465576e29433ae5e
[INFO] running `Command { std: "docker" "start" "-a" "acc7cd54be402887b80790ba897a70593dcc57ac80287f82465576e29433ae5e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.97
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling pin-project-lite v0.2.6
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling smallvec v1.6.1
[INFO] [stderr]    Compiling anyhow v1.0.41
[INFO] [stderr]    Compiling async-trait v0.1.50
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling cache-padded v1.1.1
[INFO] [stderr]    Compiling once_cell v1.8.0
[INFO] [stderr]    Compiling bytes v1.0.1
[INFO] [stderr]    Compiling instant v0.1.9
[INFO] [stderr]    Compiling tokio v1.7.0
[INFO] [stderr]    Compiling futures-micro v0.5.0
[INFO] [stderr]    Compiling async-oneshot v0.5.0
[INFO] [stderr]    Compiling lock_api v0.4.4
[INFO] [stderr]    Compiling concurrent-queue v1.2.2
[INFO] [stderr]    Compiling parking_lot_core v0.8.3
[INFO] [stderr]    Compiling mio v0.7.13
[INFO] [stderr]    Compiling signal-hook-registry v1.4.0
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling parking_lot v0.11.1
[INFO] [stderr]    Compiling tokio-macros v1.2.0
[INFO] [stderr]    Compiling aqueue v1.1.3
[INFO] [stderr]    Compiling tcpserver v1.5.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable 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 `tcpserver`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "acc7cd54be402887b80790ba897a70593dcc57ac80287f82465576e29433ae5e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acc7cd54be402887b80790ba897a70593dcc57ac80287f82465576e29433ae5e", kill_on_drop: false }`
[INFO] [stdout] acc7cd54be402887b80790ba897a70593dcc57ac80287f82465576e29433ae5e
