[INFO] fetching crate async-task 4.0.3...
[INFO] checking async-task-4.0.3 against beta for pr-78714
[INFO] extracting crate async-task 4.0.3 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate async-task 4.0.3 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 async-task 4.0.3
[INFO] finished tweaking crates.io crate async-task 4.0.3
[INFO] tweaked toml for crates.io crate async-task 4.0.3 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate crates.io crate async-task 4.0.3 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-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" "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] 9a93e9d544a8799a25ca361275303e038d052f312ae14f03e58f487487b512d4
[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" "9a93e9d544a8799a25ca361275303e038d052f312ae14f03e58f487487b512d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9a93e9d544a8799a25ca361275303e038d052f312ae14f03e58f487487b512d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a93e9d544a8799a25ca361275303e038d052f312ae14f03e58f487487b512d4", kill_on_drop: false }`
[INFO] [stdout] 9a93e9d544a8799a25ca361275303e038d052f312ae14f03e58f487487b512d4
[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=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] cb7cb0164046d1b19254ab62b4b8e2d02c6d826059a97ac06362e539e2b3120a
[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" "cb7cb0164046d1b19254ab62b4b8e2d02c6d826059a97ac06362e539e2b3120a", kill_on_drop: false }`
[INFO] [stderr]     Checking event-listener v2.4.0
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking fastrand v1.3.5
[INFO] [stderr]     Checking futures-io v0.3.5
[INFO] [stderr]     Checking async-task v3.0.0
[INFO] [stderr]     Checking easy-parallel v3.1.0
[INFO] [stderr]     Checking async-task v4.0.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking spinning_top v0.2.2
[INFO] [stderr]     Checking nb-connect v1.0.0
[INFO] [stderr]     Checking polling v1.0.3
[INFO] [stderr]     Checking signal-hook-registry v1.2.1
[INFO] [stderr]     Checking flume v0.9.0
[INFO] [stderr]     Checking async-channel v1.4.2
[INFO] [stderr]     Checking async-mutex v1.3.0
[INFO] [stderr]     Checking async-semaphore v1.1.0
[INFO] [stderr]     Checking signal-hook v0.1.16
[INFO] [stderr]     Checking async-rwlock v1.1.0
[INFO] [stderr]     Checking async-barrier v1.0.1
[INFO] [stderr]     Checking async-lock v2.1.3
[INFO] [stderr]     Checking futures-lite v1.7.0
[INFO] [stderr]     Checking async-io v1.1.2
[INFO] [stderr]     Checking blocking v1.0.0
[INFO] [stderr]     Checking async-executor v1.1.1
[INFO] [stderr]     Checking async-fs v1.3.0
[INFO] [stderr]     Checking async-process v1.0.0
[INFO] [stderr]     Checking async-net v1.3.0
[INFO] [stderr]     Checking smol v1.0.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> benches/spawn.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[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 `async-task`
[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" "cb7cb0164046d1b19254ab62b4b8e2d02c6d826059a97ac06362e539e2b3120a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cb7cb0164046d1b19254ab62b4b8e2d02c6d826059a97ac06362e539e2b3120a", kill_on_drop: false }`
[INFO] [stdout] cb7cb0164046d1b19254ab62b4b8e2d02c6d826059a97ac06362e539e2b3120a