[INFO] fetching crate juliex 0.3.0-alpha.8...
[INFO] checking juliex-0.3.0-alpha.8 against beta for pr-78714
[INFO] extracting crate juliex 0.3.0-alpha.8 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate juliex 0.3.0-alpha.8 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 juliex 0.3.0-alpha.8
[INFO] finished tweaking crates.io crate juliex 0.3.0-alpha.8
[INFO] tweaked toml for crates.io crate juliex 0.3.0-alpha.8 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate crates.io crate juliex 0.3.0-alpha.8 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-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 67d0ebd5d3312105479ba78ae26fe9ea343afde092f0403817029d0c088cd5f1
[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" "67d0ebd5d3312105479ba78ae26fe9ea343afde092f0403817029d0c088cd5f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "67d0ebd5d3312105479ba78ae26fe9ea343afde092f0403817029d0c088cd5f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "67d0ebd5d3312105479ba78ae26fe9ea343afde092f0403817029d0c088cd5f1", kill_on_drop: false }`
[INFO] [stdout] 67d0ebd5d3312105479ba78ae26fe9ea343afde092f0403817029d0c088cd5f1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 9266c1e3047d69dd5e8708a06ea00d73c9517c9b316985010b795c88da1719bb
[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" "9266c1e3047d69dd5e8708a06ea00d73c9517c9b316985010b795c88da1719bb", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.60
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.17
[INFO] [stderr]     Checking smallvec v0.6.9
[INFO] [stderr]     Checking async-ready v2.1.0
[INFO] [stderr]     Checking async-datagram v2.2.0
[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]     Checking rand_jitter v0.1.3
[INFO] [stderr]    Compiling quote v0.6.12
[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/async-ready-2.1.0/src/lib.rs:42:1
[INFO] [stdout]    |
[INFO] [stdout] 42 | #![feature(futures_api)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/async-datagram-2.2.0/src/lib.rs:43:1
[INFO] [stdout]    |
[INFO] [stdout] 43 | #![feature(futures_api)]
[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] [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-datagram`
[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" "9266c1e3047d69dd5e8708a06ea00d73c9517c9b316985010b795c88da1719bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9266c1e3047d69dd5e8708a06ea00d73c9517c9b316985010b795c88da1719bb", kill_on_drop: false }`
[INFO] [stdout] 9266c1e3047d69dd5e8708a06ea00d73c9517c9b316985010b795c88da1719bb