[INFO] fetching crate polymer-core 0.1.0...
[INFO] checking polymer-core-0.1.0 against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] extracting crate polymer-core 0.1.0 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate polymer-core 0.1.0 on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "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-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3cb765258c4f9b23b232756136c26604e71117765e91c2d470ad6f31c6ce17e1
[INFO] running `Command { std: "docker" "start" "-a" "3cb765258c4f9b23b232756136c26604e71117765e91c2d470ad6f31c6ce17e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3cb765258c4f9b23b232756136c26604e71117765e91c2d470ad6f31c6ce17e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3cb765258c4f9b23b232756136c26604e71117765e91c2d470ad6f31c6ce17e1", kill_on_drop: false }`
[INFO] [stdout] 3cb765258c4f9b23b232756136c26604e71117765e91c2d470ad6f31c6ce17e1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 869c98d7fd24c8dfd9f386e7c8715ddf1de78f3ede15e690f4e797d551d3dc52
[INFO] running `Command { std: "docker" "start" "-a" "869c98d7fd24c8dfd9f386e7c8715ddf1de78f3ede15e690f4e797d551d3dc52", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core v0.3.15
[INFO] [stderr]     Checking 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[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: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `polymer-core`
[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 E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "869c98d7fd24c8dfd9f386e7c8715ddf1de78f3ede15e690f4e797d551d3dc52", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "869c98d7fd24c8dfd9f386e7c8715ddf1de78f3ede15e690f4e797d551d3dc52", kill_on_drop: false }`
[INFO] [stdout] 869c98d7fd24c8dfd9f386e7c8715ddf1de78f3ede15e690f4e797d551d3dc52