[INFO] fetching crate srcu 0.1.0...
[INFO] testing srcu-0.1.0 against try#dec9417b8611e34e787a3e4c37686b5131f9e5c5 for pr-154210-2
[INFO] extracting crate srcu 0.1.0 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate srcu 0.1.0
[INFO] finished tweaking crates.io crate srcu 0.1.0
[INFO] tweaked toml for crates.io crate srcu 0.1.0 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate srcu 0.1.0 on toolchain dec9417b8611e34e787a3e4c37686b5131f9e5c5
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+dec9417b8611e34e787a3e4c37686b5131f9e5c5" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+dec9417b8611e34e787a3e4c37686b5131f9e5c5" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 1 package to latest compatible version
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+dec9417b8611e34e787a3e4c37686b5131f9e5c5" "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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+dec9417b8611e34e787a3e4c37686b5131f9e5c5" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 80ed9a6154590c4dc3b0db09e97f3084f6f8f5ea2b19fb5eb7d916f2838cbecb
[INFO] running `Command { std: "docker" "start" "-a" "80ed9a6154590c4dc3b0db09e97f3084f6f8f5ea2b19fb5eb7d916f2838cbecb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "80ed9a6154590c4dc3b0db09e97f3084f6f8f5ea2b19fb5eb7d916f2838cbecb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "80ed9a6154590c4dc3b0db09e97f3084f6f8f5ea2b19fb5eb7d916f2838cbecb", kill_on_drop: false }`
[INFO] [stdout] 80ed9a6154590c4dc3b0db09e97f3084f6f8f5ea2b19fb5eb7d916f2838cbecb
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+dec9417b8611e34e787a3e4c37686b5131f9e5c5" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 10f1dcb8d7b5a942c89c5a3484665214e5f47f5e327b7dc79702eba3fea624b1
[INFO] running `Command { std: "docker" "start" "-a" "10f1dcb8d7b5a942c89c5a3484665214e5f47f5e327b7dc79702eba3fea624b1", kill_on_drop: false }`
[INFO] [stderr]    Compiling barrier v0.1.0
[INFO] [stderr]    Compiling srcu v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `hash_extract_if` has been stable since 1.88.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(hash_extract_if)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `lazy_cell` has been stable since 1.80.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(lazy_cell)]
[INFO] [stdout]   |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:170:9
[INFO] [stdout]     |
[INFO] [stdout] 170 |     let _ = event.1.wait(event.0.lock().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] 170 |     let _unused = event.1.wait(event.0.lock().unwrap());
[INFO] [stdout]     |          ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 170 -     let _ = event.1.wait(event.0.lock().unwrap());
[INFO] [stdout] 170 +     drop(event.1.wait(event.0.lock().unwrap()));
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:232:13
[INFO] [stdout]     |
[INFO] [stdout] 232 |         let _ = RCU_GP_EVENT.wait(RCU_GP_COND.lock().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] 232 |         let _unused = RCU_GP_EVENT.wait(RCU_GP_COND.lock().unwrap());
[INFO] [stdout]     |              ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 232 -         let _ = RCU_GP_EVENT.wait(RCU_GP_COND.lock().unwrap());
[INFO] [stdout] 232 +         drop(RCU_GP_EVENT.wait(RCU_GP_COND.lock().unwrap()));
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:253:37
[INFO] [stdout]     |
[INFO] [stdout] 253 | ...                   let _ = RCU_CALL_READY_EVENT
[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] 253 |                                 let _unused = RCU_CALL_READY_EVENT
[INFO] [stdout]     |                                      ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 253 ~                                 drop(RCU_CALL_READY_EVENT
[INFO] [stdout] 254 ~                                     .wait(RCU_CALL_READY_EVENT_COND.lock().unwrap()));
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: non-binding let on a synchronization lock
[INFO] [stdout]    --> src/lib.rs:276:37
[INFO] [stdout]     |
[INFO] [stdout] 276 | ...                   let _ = RCU_CALL_READY_EVENT
[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] 276 |                                 let _unused = RCU_CALL_READY_EVENT
[INFO] [stdout]     |                                      ++++++
[INFO] [stdout] help: consider immediately dropping the value
[INFO] [stdout]     |
[INFO] [stdout] 276 ~                                 drop(RCU_CALL_READY_EVENT
[INFO] [stdout] 277 ~                                     .wait(RCU_CALL_READY_EVENT_COND.lock().unwrap()));
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `srcu` (lib) due to 4 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "10f1dcb8d7b5a942c89c5a3484665214e5f47f5e327b7dc79702eba3fea624b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "10f1dcb8d7b5a942c89c5a3484665214e5f47f5e327b7dc79702eba3fea624b1", kill_on_drop: false }`
[INFO] [stdout] 10f1dcb8d7b5a942c89c5a3484665214e5f47f5e327b7dc79702eba3fea624b1