[INFO] fetching crate dumbnet 0.1.0...
[INFO] checking dumbnet-0.1.0 against beta for pr-78714
[INFO] extracting crate dumbnet 0.1.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate dumbnet 0.1.0 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 dumbnet 0.1.0
[INFO] finished tweaking crates.io crate dumbnet 0.1.0
[INFO] tweaked toml for crates.io crate dumbnet 0.1.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate dumbnet 0.1.0 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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 0f11a7f177f8fa43b2ee8f086205b645ad95da408799d2862a7629e1f74edf70
[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" "0f11a7f177f8fa43b2ee8f086205b645ad95da408799d2862a7629e1f74edf70", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0f11a7f177f8fa43b2ee8f086205b645ad95da408799d2862a7629e1f74edf70", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0f11a7f177f8fa43b2ee8f086205b645ad95da408799d2862a7629e1f74edf70", kill_on_drop: false }`
[INFO] [stdout] 0f11a7f177f8fa43b2ee8f086205b645ad95da408799d2862a7629e1f74edf70
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] c0bdbce7cfd3e04610cbc72ca8eb7f904c9e18015e4dbf876e5ae64108b733d6
[INFO] running `Command { std: "docker" "start" "-a" "c0bdbce7cfd3e04610cbc72ca8eb7f904c9e18015e4dbf876e5ae64108b733d6", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling syn v1.0.11
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]    Compiling num-traits v0.2.10
[INFO] [stderr]     Checking itertools v0.8.2
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking console v0.9.1
[INFO] [stderr]     Checking indicatif v0.13.0
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]     Checking generic-array v0.13.2
[INFO] [stderr]     Checking bincode v1.2.1
[INFO] [stderr]     Checking numeric-array v0.4.2
[INFO] [stderr]     Checking dumbnet v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(trait_alias)]
[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 `dumbnet`
[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] [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: build failed
[INFO] running `Command { std: "docker" "inspect" "c0bdbce7cfd3e04610cbc72ca8eb7f904c9e18015e4dbf876e5ae64108b733d6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c0bdbce7cfd3e04610cbc72ca8eb7f904c9e18015e4dbf876e5ae64108b733d6", kill_on_drop: false }`
[INFO] [stdout] c0bdbce7cfd3e04610cbc72ca8eb7f904c9e18015e4dbf876e5ae64108b733d6