[INFO] fetching crate polymer-core 0.1.0...
[INFO] testing polymer-core-0.1.0 against 1.91.0 for beta-1.92-2
[INFO] extracting crate polymer-core 0.1.0 into /workspace/builds/worker-7-tc1/source
[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-7-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate polymer-core 0.1.0 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 1 package to latest compatible version
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 53f2824632da0177efaa256030d2b87513f1867a2c6ff742ae93214f50704220
[INFO] running `Command { std: "docker" "start" "-a" "53f2824632da0177efaa256030d2b87513f1867a2c6ff742ae93214f50704220", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "53f2824632da0177efaa256030d2b87513f1867a2c6ff742ae93214f50704220", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "53f2824632da0177efaa256030d2b87513f1867a2c6ff742ae93214f50704220", kill_on_drop: false }`
[INFO] [stdout] 53f2824632da0177efaa256030d2b87513f1867a2c6ff742ae93214f50704220
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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" "RUSTDOCFLAGS=--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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ec84e62d934135739155dbb06af72cbf2cfd95ef8a1b7e2ffddb21f427741858
[INFO] running `Command { std: "docker" "start" "-a" "ec84e62d934135739155dbb06af72cbf2cfd95ef8a1b7e2ffddb21f427741858", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core v0.3.31
[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: removed in 1.54.0; see <https://github.com/rust-lang/rust/pull/85109> for more information
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable 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] 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` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "ec84e62d934135739155dbb06af72cbf2cfd95ef8a1b7e2ffddb21f427741858", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ec84e62d934135739155dbb06af72cbf2cfd95ef8a1b7e2ffddb21f427741858", kill_on_drop: false }`
[INFO] [stdout] ec84e62d934135739155dbb06af72cbf2cfd95ef8a1b7e2ffddb21f427741858
