[INFO] fetching crate tls-async 0.3.0-alpha.7...
[INFO] checking tls-async-0.3.0-alpha.7 against 1.55.0 for beta-1.56-3
[INFO] extracting crate tls-async 0.3.0-alpha.7 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate tls-async 0.3.0-alpha.7 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] started tweaking crates.io crate tls-async 0.3.0-alpha.7
[INFO] finished tweaking crates.io crate tls-async 0.3.0-alpha.7
[INFO] tweaked toml for crates.io crate tls-async 0.3.0-alpha.7 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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] ca13462bce16cbe8fe4fa0d73b8add909b5ca60672b6ea6552245fa6168bb617
[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" "ca13462bce16cbe8fe4fa0d73b8add909b5ca60672b6ea6552245fa6168bb617", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ca13462bce16cbe8fe4fa0d73b8add909b5ca60672b6ea6552245fa6168bb617", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca13462bce16cbe8fe4fa0d73b8add909b5ca60672b6ea6552245fa6168bb617", kill_on_drop: false }`
[INFO] [stdout] ca13462bce16cbe8fe4fa0d73b8add909b5ca60672b6ea6552245fa6168bb617
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "check" "--frozen" "--all" "--all-targets" "--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] 909820e4a9e5e7991180687c93c44d0d488ff38cdf5928c71b5694c7e9332187
[INFO] running `Command { std: "docker" "start" "-a" "909820e4a9e5e7991180687c93c44d0d488ff38cdf5928c71b5694c7e9332187", kill_on_drop: false }`
[INFO] [stderr]     Checking async-ready v3.0.0
[INFO] [stderr]     Checking async-datagram v3.0.0
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking env_logger v0.5.13
[INFO] [stderr]     Checking native-tls v0.2.8
[INFO] [stderr]     Checking tokio-threadpool v0.1.18
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking tokio-io v0.1.13
[INFO] [stderr]     Checking tokio-reactor v0.1.12
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking tokio-codec v0.1.2
[INFO] [stderr]     Checking tokio-fs v0.1.7
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking tokio-tcp v0.1.4
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking romio v0.3.0-alpha.10
[INFO] [stderr]     Checking tls-async v0.3.0-alpha.7 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:17:1
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(async_await)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[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 `tls-async` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "909820e4a9e5e7991180687c93c44d0d488ff38cdf5928c71b5694c7e9332187", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "909820e4a9e5e7991180687c93c44d0d488ff38cdf5928c71b5694c7e9332187", kill_on_drop: false }`
[INFO] [stdout] 909820e4a9e5e7991180687c93c44d0d488ff38cdf5928c71b5694c7e9332187
