[INFO] cloning repository https://github.com/aprimadi/disk-queue
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/aprimadi/disk-queue" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faprimadi%2Fdisk-queue", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faprimadi%2Fdisk-queue'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7b66ebdff4ca41f4fd0f0a2149b99951b0693401
[INFO] testing aprimadi/disk-queue against try#db823df02fd0c2cf67b43025ac3fef3f2d743245 for pr-150681
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faprimadi%2Fdisk-queue" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/aprimadi/disk-queue
[INFO] finished tweaking git repo https://github.com/aprimadi/disk-queue
[INFO] tweaked toml for git repo https://github.com/aprimadi/disk-queue written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/aprimadi/disk-queue on toolchain db823df02fd0c2cf67b43025ac3fef3f2d743245
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/aprimadi/disk-queue 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" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] testing aprimadi/disk-queue against try#db823df02fd0c2cf67b43025ac3fef3f2d743245 for pr-150681
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faprimadi%2Fdisk-queue" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/aprimadi/disk-queue
[INFO] finished tweaking git repo https://github.com/aprimadi/disk-queue
[INFO] tweaked toml for git repo https://github.com/aprimadi/disk-queue written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/aprimadi/disk-queue on toolchain db823df02fd0c2cf67b43025ac3fef3f2d743245
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/aprimadi/disk-queue 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" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded once_cell v1.14.0
[INFO] [stderr]   Downloaded criterion-plot v0.4.5
[INFO] [stderr]   Downloaded plotters v0.3.3
[INFO] [stderr]   Downloaded criterion v0.3.6
[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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1e61b39b0005c1c86f3dd330d8f970e81c7fbeffccdc5d3da97aff75b804a425
[INFO] running `Command { std: "docker" "start" "-a" "1e61b39b0005c1c86f3dd330d8f970e81c7fbeffccdc5d3da97aff75b804a425", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1e61b39b0005c1c86f3dd330d8f970e81c7fbeffccdc5d3da97aff75b804a425", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e61b39b0005c1c86f3dd330d8f970e81c7fbeffccdc5d3da97aff75b804a425", kill_on_drop: false }`
[INFO] [stdout] 1e61b39b0005c1c86f3dd330d8f970e81c7fbeffccdc5d3da97aff75b804a425
[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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d6f8c64812f153d2ed996a206e1155cce2e55150e878b55d76d390c104dc0da9
[INFO] running `Command { std: "docker" "start" "-a" "d6f8c64812f153d2ed996a206e1155cce2e55150e878b55d76d390c104dc0da9", kill_on_drop: false }`
[INFO] [stderr]    Compiling memmap v0.7.0
[INFO] [stderr]    Compiling 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)]` (part of `#[deny(let_underscore)]`) 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] running `Command { std: "docker" "inspect" "d6f8c64812f153d2ed996a206e1155cce2e55150e878b55d76d390c104dc0da9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d6f8c64812f153d2ed996a206e1155cce2e55150e878b55d76d390c104dc0da9", kill_on_drop: false }`
[INFO] [stdout] d6f8c64812f153d2ed996a206e1155cce2e55150e878b55d76d390c104dc0da9