[INFO] fetching crate polymer-core 0.1.0...
[INFO] testing polymer-core-0.1.0 against beta-2021-08-01 for beta-1.55-1
[INFO] extracting crate polymer-core 0.1.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate polymer-core 0.1.0 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "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-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2a098c18de91c6424d7c9c1f121cf7f3d9eb5ed26da95ac95139d364ca4568c0
[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" "2a098c18de91c6424d7c9c1f121cf7f3d9eb5ed26da95ac95139d364ca4568c0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2a098c18de91c6424d7c9c1f121cf7f3d9eb5ed26da95ac95139d364ca4568c0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a098c18de91c6424d7c9c1f121cf7f3d9eb5ed26da95ac95139d364ca4568c0", kill_on_drop: false }`
[INFO] [stdout] 2a098c18de91c6424d7c9c1f121cf7f3d9eb5ed26da95ac95139d364ca4568c0
[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=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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d6064c58cb65fffff7f1473e11c6da27973c7abf6602ea3855288a8fa6dc59a2
[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" "d6064c58cb65fffff7f1473e11c6da27973c7abf6602ea3855288a8fa6dc59a2", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core v0.3.16
[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" "d6064c58cb65fffff7f1473e11c6da27973c7abf6602ea3855288a8fa6dc59a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d6064c58cb65fffff7f1473e11c6da27973c7abf6602ea3855288a8fa6dc59a2", kill_on_drop: false }`
[INFO] [stdout] d6064c58cb65fffff7f1473e11c6da27973c7abf6602ea3855288a8fa6dc59a2
