[INFO] fetching crate oncemutex 0.1.1...
[INFO] checking oncemutex-0.1.1 against master#30f74ff0dc4d66debc8b50724c446f817e5f75f4 for pr-121848-1
[INFO] extracting crate oncemutex 0.1.1 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate oncemutex 0.1.1 on toolchain 30f74ff0dc4d66debc8b50724c446f817e5f75f4
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate oncemutex 0.1.1
[INFO] finished tweaking crates.io crate oncemutex 0.1.1
[INFO] tweaked toml for crates.io crate oncemutex 0.1.1 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4572f1db23c7d9f39cc9c51d70d6348cfb7df6c67f65057fe3f30535c8fef96a
[INFO] running `Command { std: "docker" "start" "-a" "4572f1db23c7d9f39cc9c51d70d6348cfb7df6c67f65057fe3f30535c8fef96a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4572f1db23c7d9f39cc9c51d70d6348cfb7df6c67f65057fe3f30535c8fef96a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4572f1db23c7d9f39cc9c51d70d6348cfb7df6c67f65057fe3f30535c8fef96a", kill_on_drop: false }`
[INFO] [stdout] 4572f1db23c7d9f39cc9c51d70d6348cfb7df6c67f65057fe3f30535c8fef96a
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b7824cef6b9e771045ba0d8e9a8156365577ad4707e76d5b9c5fe580e1e81f63
[INFO] running `Command { std: "docker" "start" "-a" "b7824cef6b9e771045ba0d8e9a8156365577ad4707e76d5b9c5fe580e1e81f63", kill_on_drop: false }`
[INFO] [stderr]     Checking oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: the item `test` is imported redundantly
[INFO] [stdout]    --> src/lib.rs:174:10
[INFO] [stdout]     |
[INFO] [stdout] 23  | extern crate test;
[INFO] [stdout]     | ------------------ the item `test` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 174 |     use {test};
[INFO] [stdout]     |          ^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:1:23
[INFO] [stdout]     |
[INFO] [stdout] 1   | #![deny(missing_docs, warnings)]
[INFO] [stdout]     |                       ^^^^^^^^
[INFO] [stdout]     = note: `#[deny(unused_imports)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]   --> src/lib.rs:63:26
[INFO] [stdout]    |
[INFO] [stdout] 63 |         match self.state.compare_and_swap(UNUSED, LOCKED, SeqCst) {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]    --> src/lib.rs:103:33
[INFO] [stdout]     |
[INFO] [stdout] 103 |         if LOCKED == self.state.compare_and_swap(UNUSED, FREE, SeqCst) {
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: unnecessary `unsafe` block
[INFO] [stdout]   --> src/lib.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         unsafe { self.data.into_inner() }
[INFO] [stdout]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(unused_unsafe)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]   --> src/lib.rs:63:26
[INFO] [stdout]    |
[INFO] [stdout] 63 |         match self.state.compare_and_swap(UNUSED, LOCKED, SeqCst) {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:1:23
[INFO] [stdout]    |
[INFO] [stdout] 1  | #![deny(missing_docs, warnings)]
[INFO] [stdout]    |                       ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]    --> src/lib.rs:103:33
[INFO] [stdout]     |
[INFO] [stdout] 103 |         if LOCKED == self.state.compare_and_swap(UNUSED, FREE, SeqCst) {
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]   --> src/lib.rs:81:32
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { let _ = self.lock.lock(); }
[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] 81 |         if self.locked() { let _unused = self.lock.lock(); }
[INFO] [stdout]    |                                ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { drop(self.lock.lock()); }
[INFO] [stdout]    |                            ~~~~~                +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: unused unary operation that must be used
[INFO] [stdout]    --> src/lib.rs:199:9
[INFO] [stdout]     |
[INFO] [stdout] 199 |         *mutex;
[INFO] [stdout]     |         ^^^^^^ the unary operation produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[deny(unused_must_use)]` implied by `#[deny(warnings)]`
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 199 |         let _ = *mutex;
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 6 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `oncemutex` (lib test) due to 7 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: unnecessary `unsafe` block
[INFO] [stdout]   --> src/lib.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         unsafe { self.data.into_inner() }
[INFO] [stdout]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(unused_unsafe)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]   --> src/lib.rs:81:32
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { let _ = self.lock.lock(); }
[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] 81 |         if self.locked() { let _unused = self.lock.lock(); }
[INFO] [stdout]    |                                ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { drop(self.lock.lock()); }
[INFO] [stdout]    |                            ~~~~~                +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `oncemutex` (lib) due to 5 previous errors
[INFO] running `Command { std: "docker" "inspect" "b7824cef6b9e771045ba0d8e9a8156365577ad4707e76d5b9c5fe580e1e81f63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b7824cef6b9e771045ba0d8e9a8156365577ad4707e76d5b9c5fe580e1e81f63", kill_on_drop: false }`
[INFO] [stdout] b7824cef6b9e771045ba0d8e9a8156365577ad4707e76d5b9c5fe580e1e81f63
[INFO] checking oncemutex-0.1.1 against try#72eda894eb3548c7ba774079ce0afab42958d4ee for pr-121848-1
[INFO] extracting crate oncemutex 0.1.1 into /workspace/builds/worker-6-tc2/source
[INFO] validating manifest of crates.io crate oncemutex 0.1.1 on toolchain 72eda894eb3548c7ba774079ce0afab42958d4ee
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate oncemutex 0.1.1
[INFO] finished tweaking crates.io crate oncemutex 0.1.1
[INFO] tweaked toml for crates.io crate oncemutex 0.1.1 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 888be3685fe30da4a05ef37633d9adc9b073e18d2330751e9a6e91b239690221
[INFO] running `Command { std: "docker" "start" "-a" "888be3685fe30da4a05ef37633d9adc9b073e18d2330751e9a6e91b239690221", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "888be3685fe30da4a05ef37633d9adc9b073e18d2330751e9a6e91b239690221", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "888be3685fe30da4a05ef37633d9adc9b073e18d2330751e9a6e91b239690221", kill_on_drop: false }`
[INFO] [stdout] 888be3685fe30da4a05ef37633d9adc9b073e18d2330751e9a6e91b239690221
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f3eb965d4d05d6f5d2beb01368ebdbb26967d1596b941e5b9eaa6b8efef5a59e
[INFO] running `Command { std: "docker" "start" "-a" "f3eb965d4d05d6f5d2beb01368ebdbb26967d1596b941e5b9eaa6b8efef5a59e", kill_on_drop: false }`
[INFO] [stderr]     Checking oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: the item `test` is imported redundantly
[INFO] [stdout]    --> src/lib.rs:174:10
[INFO] [stdout]     |
[INFO] [stdout] 23  | extern crate test;
[INFO] [stdout]     | ------------------ the item `test` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 174 |     use {test};
[INFO] [stdout]     |          ^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:1:23
[INFO] [stdout]     |
[INFO] [stdout] 1   | #![deny(missing_docs, warnings)]
[INFO] [stdout]     |                       ^^^^^^^^
[INFO] [stdout]     = note: `#[deny(unused_imports)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]   --> src/lib.rs:63:26
[INFO] [stdout]    |
[INFO] [stdout] 63 |         match self.state.compare_and_swap(UNUSED, LOCKED, SeqCst) {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]    --> src/lib.rs:103:33
[INFO] [stdout]     |
[INFO] [stdout] 103 |         if LOCKED == self.state.compare_and_swap(UNUSED, FREE, SeqCst) {
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: unnecessary `unsafe` block
[INFO] [stdout]   --> src/lib.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         unsafe { self.data.into_inner() }
[INFO] [stdout]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(unused_unsafe)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]   --> src/lib.rs:63:26
[INFO] [stdout]    |
[INFO] [stdout] 63 |         match self.state.compare_and_swap(UNUSED, LOCKED, SeqCst) {
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:1:23
[INFO] [stdout]    |
[INFO] [stdout] 1  | #![deny(missing_docs, warnings)]
[INFO] [stdout]    |                       ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated method `std::sync::atomic::AtomicUsize::compare_and_swap`: Use `compare_exchange` or `compare_exchange_weak` instead
[INFO] [stdout]    --> src/lib.rs:103:33
[INFO] [stdout]     |
[INFO] [stdout] 103 |         if LOCKED == self.state.compare_and_swap(UNUSED, FREE, SeqCst) {
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]   --> src/lib.rs:81:32
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { let _ = self.lock.lock(); }
[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] 81 |         if self.locked() { let _unused = self.lock.lock(); }
[INFO] [stdout]    |                                ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { drop(self.lock.lock()); }
[INFO] [stdout]    |                            ~~~~~                +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: unused unary operation that must be used
[INFO] [stdout]    --> src/lib.rs:199:9
[INFO] [stdout]     |
[INFO] [stdout] 199 |         *mutex;
[INFO] [stdout]     |         ^^^^^^ the unary operation produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[deny(unused_must_use)]` implied by `#[deny(warnings)]`
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 199 |         let _ = *mutex;
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 6 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: unnecessary `unsafe` block
[INFO] [stdout]   --> src/lib.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         unsafe { self.data.into_inner() }
[INFO] [stdout]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(unused_unsafe)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `oncemutex` (lib test) due to 7 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/lib.rs:81:32
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { let _ = self.lock.lock(); }
[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] 81 |         if self.locked() { let _unused = self.lock.lock(); }
[INFO] [stdout]    |                                ~~~~~~~
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]    |
[INFO] [stdout] 81 |         if self.locked() { drop(self.lock.lock()); }
[INFO] [stdout]    |                            ~~~~~                +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `oncemutex` (lib) due to 5 previous errors
[INFO] running `Command { std: "docker" "inspect" "f3eb965d4d05d6f5d2beb01368ebdbb26967d1596b941e5b9eaa6b8efef5a59e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f3eb965d4d05d6f5d2beb01368ebdbb26967d1596b941e5b9eaa6b8efef5a59e", kill_on_drop: false }`
[INFO] [stdout] f3eb965d4d05d6f5d2beb01368ebdbb26967d1596b941e5b9eaa6b8efef5a59e
