[INFO] fetching crate primal-tokio 0.1.0...
[INFO] testing primal-tokio-0.1.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate primal-tokio 0.1.0 into /workspace/builds/worker-47/source
[INFO] validating manifest of crates.io crate primal-tokio 0.1.0 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 primal-tokio 0.1.0
[INFO] finished tweaking crates.io crate primal-tokio 0.1.0
[INFO] tweaked toml for crates.io crate primal-tokio 0.1.0 written to /workspace/builds/worker-47/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] [stderr]     Blocking waiting for file lock on package cache
[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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded pin-project-lite v0.1.12
[INFO] [stderr]   Downloaded primal-estimate v0.2.1
[INFO] [stderr]   Downloaded primal v0.2.3
[INFO] [stderr]   Downloaded bytes v0.5.6
[INFO] [stderr]   Downloaded hamming v0.1.3
[INFO] [stderr]   Downloaded primal-check v0.2.3
[INFO] [stderr]   Downloaded primal-sieve v0.2.9
[INFO] [stderr]   Downloaded tokio-macros v0.2.6
[INFO] [stderr]   Downloaded primal-bit v0.2.4
[INFO] [stderr]   Downloaded tokio v0.2.25
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-47/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-47/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] f8284b3b8eacf16331c41c6c6987ca59fafb4c06a51e8ebe53601859ba3c5daa
[INFO] running `Command { std: "docker" "start" "-a" "f8284b3b8eacf16331c41c6c6987ca59fafb4c06a51e8ebe53601859ba3c5daa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f8284b3b8eacf16331c41c6c6987ca59fafb4c06a51e8ebe53601859ba3c5daa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f8284b3b8eacf16331c41c6c6987ca59fafb4c06a51e8ebe53601859ba3c5daa", kill_on_drop: false }`
[INFO] [stdout] f8284b3b8eacf16331c41c6c6987ca59fafb4c06a51e8ebe53601859ba3c5daa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-47/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-47/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] [stdout] 856358a22a18873bc238be6098ed4a692b19bef6c1c3074b2465d358e94596d3
[INFO] running `Command { std: "docker" "start" "-a" "856358a22a18873bc238be6098ed4a692b19bef6c1c3074b2465d358e94596d3", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling futures-core v0.3.17
[INFO] [stderr]    Compiling hamming v0.1.3
[INFO] [stderr]    Compiling primal-estimate v0.2.1
[INFO] [stderr]    Compiling bytes v0.5.6
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling primal-bit v0.2.4
[INFO] [stderr]    Compiling primal-sieve v0.2.9
[INFO] [stderr]    Compiling primal-check v0.2.3
[INFO] [stderr]    Compiling primal v0.2.3
[INFO] [stderr]    Compiling tokio-macros v0.2.6
[INFO] [stderr]    Compiling tokio v0.2.25
[INFO] [stderr]    Compiling primal-tokio v0.1.0 (/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[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(type_ascription)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `primal-tokio` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "856358a22a18873bc238be6098ed4a692b19bef6c1c3074b2465d358e94596d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "856358a22a18873bc238be6098ed4a692b19bef6c1c3074b2465d358e94596d3", kill_on_drop: false }`
[INFO] [stdout] 856358a22a18873bc238be6098ed4a692b19bef6c1c3074b2465d358e94596d3