[INFO] fetching crate disk-queue 0.1.1...
[INFO] checking disk-queue-0.1.1 against master#82310651b93a594a3fd69015e1562186a080d94c for pr-145770
[INFO] extracting crate disk-queue 0.1.1 into /workspace/builds/worker-6-tc1/source
[INFO] started tweaking crates.io crate disk-queue 0.1.1
[INFO] finished tweaking crates.io crate disk-queue 0.1.1
[INFO] tweaked toml for crates.io crate disk-queue 0.1.1 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate disk-queue 0.1.1 on toolchain 82310651b93a594a3fd69015e1562186a080d94c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+82310651b93a594a3fd69015e1562186a080d94c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate disk-queue 0.1.1 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" "+82310651b93a594a3fd69015e1562186a080d94c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded plotters v0.3.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+82310651b93a594a3fd69015e1562186a080d94c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c747683d95657c8525df264977c554e193d056828114abeb8589a131d7acf624
[INFO] running `Command { std: "docker" "start" "-a" "c747683d95657c8525df264977c554e193d056828114abeb8589a131d7acf624", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c747683d95657c8525df264977c554e193d056828114abeb8589a131d7acf624", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c747683d95657c8525df264977c554e193d056828114abeb8589a131d7acf624", kill_on_drop: false }`
[INFO] [stdout] c747683d95657c8525df264977c554e193d056828114abeb8589a131d7acf624
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+82310651b93a594a3fd69015e1562186a080d94c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0b636546fcb09be0f81f80b03ca64ac5935873bee08a84e1814f9d7d225de1fe
[INFO] running `Command { std: "docker" "start" "-a" "0b636546fcb09be0f81f80b03ca64ac5935873bee08a84e1814f9d7d225de1fe", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling libc v0.2.132
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling serde v1.0.144
[INFO] [stderr]    Compiling crossbeam-utils v0.8.11
[INFO] [stderr]     Checking once_cell v1.14.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.43
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling unicode-ident v1.0.3
[INFO] [stderr]    Compiling rayon-core v1.9.3
[INFO] [stderr]    Compiling quote v1.0.21
[INFO] [stderr]     Checking either v1.8.0
[INFO] [stderr]    Compiling memoffset v0.6.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.10
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling syn v1.0.99
[INFO] [stderr]     Checking ryu v1.0.11
[INFO] [stderr]    Compiling serde_json v1.0.85
[INFO] [stderr]     Checking crossbeam-channel v0.5.6
[INFO] [stderr]    Compiling rayon v1.5.3
[INFO] [stderr]     Checking plotters-backend v0.3.4
[INFO] [stderr]     Checking crossbeam-deque v0.8.2
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking itoa v1.0.3
[INFO] [stderr]     Checking regex-automata v0.1.10
[INFO] [stderr]     Checking getrandom v0.2.7
[INFO] [stderr]     Checking num_cpus v1.13.1
[INFO] [stderr]    Compiling serde_derive v1.0.144
[INFO] [stderr]     Checking unicode-width v0.1.9
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking plotters-svg v0.3.3
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]     Checking itertools v0.10.3
[INFO] [stderr]     Checking regex-syntax v0.6.27
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking ppv-lite86 v0.2.16
[INFO] [stderr]     Checking half v1.8.2
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking cast v0.3.0
[INFO] [stderr]     Checking same-file v1.0.6
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]     Checking walkdir v2.3.2
[INFO] [stderr]     Checking plotters v0.3.3
[INFO] [stderr]     Checking memmap v0.7.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking oorandom v11.1.3
[INFO] [stderr]     Checking regex v1.6.0
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking criterion-plot v0.4.5
[INFO] [stderr]     Checking disk-queue v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/page.rs:192:17
[INFO] [stdout]     |
[INFO] [stdout] 192 |             let _ = rwlatch.read().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] 192 |             let _unused = rwlatch.read().unwrap();
[INFO] [stdout]     |                  ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 192 -             let _ = rwlatch.read().unwrap();
[INFO] [stdout] 192 +             drop(rwlatch.read().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/page.rs:233:17
[INFO] [stdout]     |
[INFO] [stdout] 233 |             let _ = self.rwlatch.read().unwrap();
[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] 233 |             let _unused = self.rwlatch.read().unwrap();
[INFO] [stdout]     |                  ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 233 -             let _ = self.rwlatch.read().unwrap();
[INFO] [stdout] 233 +             drop(self.rwlatch.read().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/page.rs:242:17
[INFO] [stdout]     |
[INFO] [stdout] 242 |             let _ = self.rwlatch.write().unwrap();
[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] 242 |             let _unused = self.rwlatch.write().unwrap();
[INFO] [stdout]     |                  ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 242 -             let _ = self.rwlatch.write().unwrap();
[INFO] [stdout] 242 +             drop(self.rwlatch.write().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/page.rs:256:21
[INFO] [stdout]     |
[INFO] [stdout] 256 |                 let _ = self.rwlatch.read().unwrap();
[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] 256 |                 let _unused = self.rwlatch.read().unwrap();
[INFO] [stdout]     |                      ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 256 -                 let _ = self.rwlatch.read().unwrap();
[INFO] [stdout] 256 +                 drop(self.rwlatch.read().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/page.rs:274:21
[INFO] [stdout]     |
[INFO] [stdout] 274 |                 let _ = self.rwlatch.read().unwrap();
[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] 274 |                 let _unused = self.rwlatch.read().unwrap();
[INFO] [stdout]     |                      ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 274 -                 let _ = self.rwlatch.read().unwrap();
[INFO] [stdout] 274 +                 drop(self.rwlatch.read().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/page.rs:307:17
[INFO] [stdout]     |
[INFO] [stdout] 307 |             let _ = self.rwlatch.write().unwrap();
[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] 307 |             let _unused = self.rwlatch.write().unwrap();
[INFO] [stdout]     |                  ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 307 -             let _ = self.rwlatch.write().unwrap();
[INFO] [stdout] 307 +             drop(self.rwlatch.write().unwrap());
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `disk-queue` (lib) due to 6 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "0b636546fcb09be0f81f80b03ca64ac5935873bee08a84e1814f9d7d225de1fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0b636546fcb09be0f81f80b03ca64ac5935873bee08a84e1814f9d7d225de1fe", kill_on_drop: false }`
[INFO] [stdout] 0b636546fcb09be0f81f80b03ca64ac5935873bee08a84e1814f9d7d225de1fe
