[INFO] fetching crate rx 0.0.1...
[INFO] testing rx-0.0.1 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate rx 0.0.1 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate rx 0.0.1 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rx 0.0.1
[INFO] finished tweaking crates.io crate rx 0.0.1
[INFO] tweaked toml for crates.io crate rx 0.0.1 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] af4ced8c6b6c5671253dd9d8b3bbfb2f02e1d960dcf91d448c14415897f8372f
[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" "af4ced8c6b6c5671253dd9d8b3bbfb2f02e1d960dcf91d448c14415897f8372f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af4ced8c6b6c5671253dd9d8b3bbfb2f02e1d960dcf91d448c14415897f8372f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af4ced8c6b6c5671253dd9d8b3bbfb2f02e1d960dcf91d448c14415897f8372f", kill_on_drop: false }`
[INFO] [stdout] af4ced8c6b6c5671253dd9d8b3bbfb2f02e1d960dcf91d448c14415897f8372f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4930b9bd9d839c23d536a5517472b2d1d0b635098c87a0e412d8be39b2f8ddfa
[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" "4930b9bd9d839c23d536a5517472b2d1d0b635098c87a0e412d8be39b2f8ddfa", kill_on_drop: false }`
[INFO] [stderr]    Compiling rx v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:16:1
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(fn_traits, unboxed_closures)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/subject.rs:17:24
[INFO] [stdout]    |
[INFO] [stdout] 17 |     observers: Vec<Box<BoxedObserver<T, E>>>,
[INFO] [stdout]    |                        ^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn BoxedObserver<T, E>`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rx`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "4930b9bd9d839c23d536a5517472b2d1d0b635098c87a0e412d8be39b2f8ddfa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4930b9bd9d839c23d536a5517472b2d1d0b635098c87a0e412d8be39b2f8ddfa", kill_on_drop: false }`
[INFO] [stdout] 4930b9bd9d839c23d536a5517472b2d1d0b635098c87a0e412d8be39b2f8ddfa