[INFO] fetching crate monotron-synth 0.2.0...
[INFO] checking monotron-synth-0.2.0 against master#4e1f5d90bca45207605a88e39b1f76abcdb85d2f for pr-123962
[INFO] extracting crate monotron-synth 0.2.0 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate monotron-synth 0.2.0 on toolchain 4e1f5d90bca45207605a88e39b1f76abcdb85d2f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4e1f5d90bca45207605a88e39b1f76abcdb85d2f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate monotron-synth 0.2.0
[INFO] finished tweaking crates.io crate monotron-synth 0.2.0
[INFO] tweaked toml for crates.io crate monotron-synth 0.2.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4e1f5d90bca45207605a88e39b1f76abcdb85d2f" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 18 packages
[INFO] [stderr]       Adding bitflags v1.3.2 (latest: v2.5.0)
[INFO] [stderr]       Adding num-derive v0.3.3 (latest: v0.4.2)
[INFO] [stderr]       Adding syn v1.0.109 (latest: v2.0.60)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4e1f5d90bca45207605a88e39b1f76abcdb85d2f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded libpulse-sys v1.21.0
[INFO] [stderr]   Downloaded libpulse-simple-sys v1.21.1
[INFO] [stderr]   Downloaded libpulse-simple-binding v2.28.1
[INFO] [stderr]   Downloaded libpulse-binding v2.28.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:99613afd962a8cfa530ec1899472a458bd015a1ab0af876cf7eb06f6006d81ea" "/opt/rustwide/cargo-home/bin/cargo" "+4e1f5d90bca45207605a88e39b1f76abcdb85d2f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 61595560f0e863ea71bcc5ebbb1846c858d092763647c045687bda5ede0b9d5f
[INFO] running `Command { std: "docker" "start" "-a" "61595560f0e863ea71bcc5ebbb1846c858d092763647c045687bda5ede0b9d5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "61595560f0e863ea71bcc5ebbb1846c858d092763647c045687bda5ede0b9d5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "61595560f0e863ea71bcc5ebbb1846c858d092763647c045687bda5ede0b9d5f", kill_on_drop: false }`
[INFO] [stdout] 61595560f0e863ea71bcc5ebbb1846c858d092763647c045687bda5ede0b9d5f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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=forbid" "-e" "RUSTDOCFLAGS=--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@sha256:99613afd962a8cfa530ec1899472a458bd015a1ab0af876cf7eb06f6006d81ea" "/opt/rustwide/cargo-home/bin/cargo" "+4e1f5d90bca45207605a88e39b1f76abcdb85d2f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8ed4defc8a9ba1eefe45efc621dfe16427d7d1e8987471449c9b0079152e1252
[INFO] running `Command { std: "docker" "start" "-a" "8ed4defc8a9ba1eefe45efc621dfe16427d7d1e8987471449c9b0079152e1252", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.2.0
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling libpulse-sys v1.21.0
[INFO] [stderr]    Compiling libpulse-simple-sys v1.21.1
[INFO] [stderr]     Checking monotron-synth v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(const_fn)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]    --> src/lib.rs:359:9
[INFO] [stdout]     |
[INFO] [stdout] 359 |         (intermediate as u8)
[INFO] [stdout]     |         ^                  ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 359 -         (intermediate as u8)
[INFO] [stdout] 359 +         intermediate as u8
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `monotron-synth` (lib) due to 2 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "8ed4defc8a9ba1eefe45efc621dfe16427d7d1e8987471449c9b0079152e1252", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ed4defc8a9ba1eefe45efc621dfe16427d7d1e8987471449c9b0079152e1252", kill_on_drop: false }`
[INFO] [stdout] 8ed4defc8a9ba1eefe45efc621dfe16427d7d1e8987471449c9b0079152e1252