[INFO] fetching crate polymer-core 0.1.0...
[INFO] testing polymer-core-0.1.0 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate polymer-core 0.1.0 into /workspace/builds/worker-67/source
[INFO] validating manifest of crates.io crate polymer-core 0.1.0 on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate polymer-core 0.1.0
[INFO] finished tweaking crates.io crate polymer-core 0.1.0
[INFO] tweaked toml for crates.io crate polymer-core 0.1.0 written to /workspace/builds/worker-67/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/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" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e2d1a6563fcf4ec2e7d7645511099c3ce37dbf76a3f261bcb238e98cd4ca3026
[INFO] running `Command { std: "docker" "start" "-a" "e2d1a6563fcf4ec2e7d7645511099c3ce37dbf76a3f261bcb238e98cd4ca3026", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e2d1a6563fcf4ec2e7d7645511099c3ce37dbf76a3f261bcb238e98cd4ca3026", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2d1a6563fcf4ec2e7d7645511099c3ce37dbf76a3f261bcb238e98cd4ca3026", kill_on_drop: false }`
[INFO] [stdout] e2d1a6563fcf4ec2e7d7645511099c3ce37dbf76a3f261bcb238e98cd4ca3026
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-67/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" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] edd03c3d7139dbd3ebf6ec37fd9061324315b2d295dad74b9a3bfec72108d9a7
[INFO] running `Command { std: "docker" "start" "-a" "edd03c3d7139dbd3ebf6ec37fd9061324315b2d295dad74b9a3bfec72108d9a7", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core v0.3.17
[INFO] [stderr]    Compiling polymer-core v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:2:34
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(arbitrary_self_types, const_fn, never_type)]
[INFO] [stdout]   |                                  ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[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(arbitrary_self_types, const_fn, never_type)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `polymer-core` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "edd03c3d7139dbd3ebf6ec37fd9061324315b2d295dad74b9a3bfec72108d9a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "edd03c3d7139dbd3ebf6ec37fd9061324315b2d295dad74b9a3bfec72108d9a7", kill_on_drop: false }`
[INFO] [stdout] edd03c3d7139dbd3ebf6ec37fd9061324315b2d295dad74b9a3bfec72108d9a7