[INFO] fetching crate monotron-synth 0.2.0...
[INFO] checking monotron-synth-0.2.0 against try#3d9fdbff4f377de96b3a51174e7a64086bee9a5c for pr-81477
[INFO] extracting crate monotron-synth 0.2.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate monotron-synth 0.2.0 on toolchain 3d9fdbff4f377de96b3a51174e7a64086bee9a5c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "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-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded num-derive v0.3.3
[INFO] [stderr]   Downloaded libpulse-sys v1.18.0
[INFO] [stderr]   Downloaded libpulse-simple-sys v1.16.1
[INFO] [stderr]   Downloaded libpulse-binding v2.23.1
[INFO] [stderr]   Downloaded libpulse-simple-binding v2.23.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7178febce4bb84e43ac776fe7e0cbcf3d85adbf6dc2f2b9d1765854635db5f2c
[INFO] running `Command { std: "docker" "start" "-a" "7178febce4bb84e43ac776fe7e0cbcf3d85adbf6dc2f2b9d1765854635db5f2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7178febce4bb84e43ac776fe7e0cbcf3d85adbf6dc2f2b9d1765854635db5f2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7178febce4bb84e43ac776fe7e0cbcf3d85adbf6dc2f2b9d1765854635db5f2c", kill_on_drop: false }`
[INFO] [stdout] 7178febce4bb84e43ac776fe7e0cbcf3d85adbf6dc2f2b9d1765854635db5f2c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+3d9fdbff4f377de96b3a51174e7a64086bee9a5c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1a721225a23a819bedf0c4d043945b6b10fed0fd2964294fc9439adf188f4eaa
[INFO] running `Command { std: "docker" "start" "-a" "1a721225a23a819bedf0c4d043945b6b10fed0fd2964294fc9439adf188f4eaa", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.97
[INFO] [stderr]     Checking monotron-synth v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling libpulse-sys v1.18.0
[INFO] [stderr]    Compiling libpulse-simple-sys v1.16.1
[INFO] [stderr]    Compiling num-derive v0.3.3
[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]     |         ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 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`
[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] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "1a721225a23a819bedf0c4d043945b6b10fed0fd2964294fc9439adf188f4eaa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a721225a23a819bedf0c4d043945b6b10fed0fd2964294fc9439adf188f4eaa", kill_on_drop: false }`
[INFO] [stdout] 1a721225a23a819bedf0c4d043945b6b10fed0fd2964294fc9439adf188f4eaa