[INFO] fetching crate monotron-synth 0.2.0...
[INFO] checking monotron-synth-0.2.0 against try#6f8a6450478f69b8510c8976ab6c2a70b3b0e47c for pr-84920
[INFO] extracting crate monotron-synth 0.2.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate monotron-synth 0.2.0 on toolchain 6f8a6450478f69b8510c8976ab6c2a70b3b0e47c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "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-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded libpulse-simple-sys v1.16.1
[INFO] [stderr]   Downloaded libpulse-binding v2.23.1
[INFO] [stderr]   Downloaded libpulse-sys v1.18.0
[INFO] [stderr]   Downloaded libpulse-simple-binding v2.23.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2a1e5899a7aa5875d9c9960a9f0858bed0516d40b6c2dda96f1dd8a96a3eae4f
[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" "2a1e5899a7aa5875d9c9960a9f0858bed0516d40b6c2dda96f1dd8a96a3eae4f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2a1e5899a7aa5875d9c9960a9f0858bed0516d40b6c2dda96f1dd8a96a3eae4f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a1e5899a7aa5875d9c9960a9f0858bed0516d40b6c2dda96f1dd8a96a3eae4f", kill_on_drop: false }`
[INFO] [stdout] 2a1e5899a7aa5875d9c9960a9f0858bed0516d40b6c2dda96f1dd8a96a3eae4f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 55c06c71f9cc6ff9e6411fa0f26fb9682897ce4852dca559935a7bc4b90a38fb
[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" "55c06c71f9cc6ff9e6411fa0f26fb9682897ce4852dca559935a7bc4b90a38fb", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.94
[INFO] [stderr]    Compiling bitflags v1.2.1
[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] [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] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling num-derive v0.3.3
[INFO] [stderr]     Checking libpulse-binding v2.23.1
[INFO] [stderr]     Checking libpulse-simple-binding v2.23.0
[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] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 26.58s
[INFO] running `Command { std: "docker" "inspect" "55c06c71f9cc6ff9e6411fa0f26fb9682897ce4852dca559935a7bc4b90a38fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "55c06c71f9cc6ff9e6411fa0f26fb9682897ce4852dca559935a7bc4b90a38fb", kill_on_drop: false }`
[INFO] [stdout] 55c06c71f9cc6ff9e6411fa0f26fb9682897ce4852dca559935a7bc4b90a38fb