[INFO] fetching crate ya-ring-buf 0.1.0...
[INFO] checking ya-ring-buf-0.1.0 against master#e6e4f7ed1589e03bc2f6c5931c1a72e7947e8682 for beta-170-4
[INFO] extracting crate ya-ring-buf 0.1.0 into /workspace/builds/worker-4-tc2/source
[INFO] validating manifest of crates.io crate ya-ring-buf 0.1.0 on toolchain e6e4f7ed1589e03bc2f6c5931c1a72e7947e8682
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+e6e4f7ed1589e03bc2f6c5931c1a72e7947e8682" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ya-ring-buf 0.1.0
[INFO] finished tweaking crates.io crate ya-ring-buf 0.1.0
[INFO] tweaked toml for crates.io crate ya-ring-buf 0.1.0 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate crates.io crate ya-ring-buf 0.1.0 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" "+e6e4f7ed1589e03bc2f6c5931c1a72e7947e8682" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:19e73879b68f455e41552ea35293514db52ea292d993f571636dbffedb77a1ee" "/opt/rustwide/cargo-home/bin/cargo" "+e6e4f7ed1589e03bc2f6c5931c1a72e7947e8682" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cf6dd525bbea1e67bcc4a56d036e61a4864896137edb75c2501f8bfd6ce28bec
[INFO] running `Command { std: "docker" "start" "-a" "cf6dd525bbea1e67bcc4a56d036e61a4864896137edb75c2501f8bfd6ce28bec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cf6dd525bbea1e67bcc4a56d036e61a4864896137edb75c2501f8bfd6ce28bec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cf6dd525bbea1e67bcc4a56d036e61a4864896137edb75c2501f8bfd6ce28bec", kill_on_drop: false }`
[INFO] [stdout] cf6dd525bbea1e67bcc4a56d036e61a4864896137edb75c2501f8bfd6ce28bec
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:19e73879b68f455e41552ea35293514db52ea292d993f571636dbffedb77a1ee" "/opt/rustwide/cargo-home/bin/cargo" "+e6e4f7ed1589e03bc2f6c5931c1a72e7947e8682" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fcdfbb47682d2978e40fc689bde1b158ac8c6297fdd0bb0a903c7c962de0e24d
[INFO] running `Command { std: "docker" "start" "-a" "fcdfbb47682d2978e40fc689bde1b158ac8c6297fdd0bb0a903c7c962de0e24d", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.91
[INFO] [stderr]     Checking pin-project-lite v0.2.8
[INFO] [stderr]     Checking ya-ring-buf v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/waiter.rs:138:9
[INFO] [stdout]     |
[INFO] [stdout] 138 |                   let _ = self
[INFO] [stdout]     |  _____________________^___^
[INFO] [stdout]     | |                     |
[INFO] [stdout]     | |                     this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout] 139 | |                     .cond
[INFO] [stdout] 140 | |                     .wait_while(m, |_| !self.flag.swap(false, Ordering::Acquire))
[INFO] [stdout] 141 | |                     .unwrap();
[INFO] [stdout]     | |_____________________________^ this binding will immediately drop the value assigned to it
[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] 138 |                 let _unused = self
[INFO] [stdout]     |                     ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 138 ~                 drop(self
[INFO] [stdout] 139 |                     .cond
[INFO] [stdout] 140 |                     .wait_while(m, |_| !self.flag.swap(false, Ordering::Acquire))
[INFO] [stdout] 141 ~                     .unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/waiter.rs:146:8
[INFO] [stdout]     |
[INFO] [stdout] 146 |             let _ = self.mutex.lock().unwrap();
[INFO] [stdout]     |                 ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^ this binding will immediately drop the value assigned to it
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 this lock is not assigned to a binding and is immediately dropped
[INFO] [stdout]     |
[INFO] [stdout] help: consider binding to an unused variable to avoid immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 146 |             let _unused = self.mutex.lock().unwrap();
[INFO] [stdout]     |                 ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 146 |             drop(self.mutex.lock().unwrap());
[INFO] [stdout]     |             ~~~~~                          +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ya-ring-buf` (lib) due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "fcdfbb47682d2978e40fc689bde1b158ac8c6297fdd0bb0a903c7c962de0e24d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fcdfbb47682d2978e40fc689bde1b158ac8c6297fdd0bb0a903c7c962de0e24d", kill_on_drop: false }`
[INFO] [stdout] fcdfbb47682d2978e40fc689bde1b158ac8c6297fdd0bb0a903c7c962de0e24d
