[INFO] cloning repository https://github.com/MacPardo/dcb.rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/MacPardo/dcb.rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMacPardo%2Fdcb.rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMacPardo%2Fdcb.rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9888c086417274e65b7b05c1956b3d50f2b97734
[INFO] checking MacPardo/dcb.rs/9888c086417274e65b7b05c1956b3d50f2b97734 against master#f609b7e0586f81fefb3523e3e17adf779ac416be for pr-129466-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMacPardo%2Fdcb.rs" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MacPardo/dcb.rs on toolchain f609b7e0586f81fefb3523e3e17adf779ac416be
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/MacPardo/dcb.rs
[INFO] finished tweaking git repo https://github.com/MacPardo/dcb.rs
[INFO] tweaked toml for git repo https://github.com/MacPardo/dcb.rs written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/MacPardo/dcb.rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 00c365080c3e8f55b72e0a1eaef1ea3acca30a324c74b7e350f76fcb2d076836
[INFO] running `Command { std: "docker" "start" "-a" "00c365080c3e8f55b72e0a1eaef1ea3acca30a324c74b7e350f76fcb2d076836", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "00c365080c3e8f55b72e0a1eaef1ea3acca30a324c74b7e350f76fcb2d076836", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "00c365080c3e8f55b72e0a1eaef1ea3acca30a324c74b7e350f76fcb2d076836", kill_on_drop: false }`
[INFO] [stdout] 00c365080c3e8f55b72e0a1eaef1ea3acca30a324c74b7e350f76fcb2d076836
[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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8a2c57931bc2f8a2ae3991d7d89668ba3362e42d45773136063609de0022610b
[INFO] running `Command { std: "docker" "start" "-a" "8a2c57931bc2f8a2ae3991d7d89668ba3362e42d45773136063609de0022610b", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling syn v1.0.38
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking ppv-lite86 v0.2.8
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]     Checking itoa v0.4.6
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking dcb v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]   --> src/msg_queue/msg_queue.rs:33:17
[INFO] [stdout]    |
[INFO] [stdout] 33 |             let _ = self.cvar.wait(queue).unwrap();
[INFO] [stdout]    |                 ^ this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(let_underscore_lock)]` on by default
[INFO] [stdout] help: consider binding to an unused variable to avoid immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 33 |             let _unused = self.cvar.wait(queue).unwrap();
[INFO] [stdout]    |                 ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 33 |             drop(self.cvar.wait(queue).unwrap());
[INFO] [stdout]    |             ~~~~~                              +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `dcb` (bin "dcb") due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]   --> src/msg_queue/msg_queue.rs:33:17
[INFO] [stdout]    |
[INFO] [stdout] 33 |             let _ = self.cvar.wait(queue).unwrap();
[INFO] [stdout]    |                 ^ this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(let_underscore_lock)]` on by default
[INFO] [stdout] help: consider binding to an unused variable to avoid immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 33 |             let _unused = self.cvar.wait(queue).unwrap();
[INFO] [stdout]    |                 ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 33 |             drop(self.cvar.wait(queue).unwrap());
[INFO] [stdout]    |             ~~~~~                              +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `dcb` (bin "dcb" test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "8a2c57931bc2f8a2ae3991d7d89668ba3362e42d45773136063609de0022610b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8a2c57931bc2f8a2ae3991d7d89668ba3362e42d45773136063609de0022610b", kill_on_drop: false }`
[INFO] [stdout] 8a2c57931bc2f8a2ae3991d7d89668ba3362e42d45773136063609de0022610b