[INFO] fetching crate rill 0.3.0...
[INFO] checking rill-0.3.0 against beta for pr-78714
[INFO] extracting crate rill 0.3.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate rill 0.3.0 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rill 0.3.0
[INFO] finished tweaking crates.io crate rill 0.3.0
[INFO] tweaked toml for crates.io crate rill 0.3.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate crates.io crate rill 0.3.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--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-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b831eef2df6f613dd5179cb2cc755c7404573296335575d168fc28856d68b1c3
[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" "b831eef2df6f613dd5179cb2cc755c7404573296335575d168fc28856d68b1c3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b831eef2df6f613dd5179cb2cc755c7404573296335575d168fc28856d68b1c3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b831eef2df6f613dd5179cb2cc755c7404573296335575d168fc28856d68b1c3", kill_on_drop: false }`
[INFO] [stdout] b831eef2df6f613dd5179cb2cc755c7404573296335575d168fc28856d68b1c3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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=forbid" "-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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 48cbe0acf08d926f4cba1c272e0ae4695899fff52b730b6d1fd80f7bd225f5a1
[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" "48cbe0acf08d926f4cba1c272e0ae4695899fff52b730b6d1fd80f7bd225f5a1", 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]     Checking futures-core v0.3.7
[INFO] [stderr]     Checking futures-sink v0.3.7
[INFO] [stderr]     Checking futures-io v0.3.7
[INFO] [stderr]    Compiling anyhow v1.0.33
[INFO] [stderr]     Checking futures-task v0.3.7
[INFO] [stderr]     Checking buf_redux v0.8.4
[INFO] [stderr]     Checking twoway v0.1.8
[INFO] [stderr]     Checking signal-hook-registry v1.2.1
[INFO] [stderr]     Checking openssl-sys v0.9.58
[INFO] [stderr]     Checking socket2 v0.3.15
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]    Compiling futures-macro v0.3.7
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling derive_more v0.99.11
[INFO] [stderr]    Compiling thiserror-impl v1.0.21
[INFO] [stderr]     Checking futures-channel v0.3.7
[INFO] [stderr]     Checking headers v0.3.2
[INFO] [stderr]     Checking serde_urlencoded v0.6.1
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking openssl v0.10.30
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking uuid v0.8.1
[INFO] [stderr]     Checking multipart v0.17.0
[INFO] [stderr]     Checking futures-util v0.3.7
[INFO] [stderr]     Checking thiserror v1.0.21
[INFO] [stderr]     Checking native-tls v0.2.4
[INFO] [stderr]     Checking tungstenite v0.11.1
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]     Checking futures-executor v0.3.7
[INFO] [stderr]     Checking h2 v0.2.7
[INFO] [stderr]     Checking tokio-tungstenite v0.11.0
[INFO] [stderr]     Checking async-tungstenite v0.9.3
[INFO] [stderr]     Checking futures v0.3.7
[INFO] [stderr]     Checking meio v0.23.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/meio-0.23.0/src/lib.rs:13:1
[INFO] [stdout]    |
[INFO] [stdout] 13 | #![feature(generators)]
[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 `meio`
[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" "48cbe0acf08d926f4cba1c272e0ae4695899fff52b730b6d1fd80f7bd225f5a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48cbe0acf08d926f4cba1c272e0ae4695899fff52b730b6d1fd80f7bd225f5a1", kill_on_drop: false }`
[INFO] [stdout] 48cbe0acf08d926f4cba1c272e0ae4695899fff52b730b6d1fd80f7bd225f5a1