[INFO] cloning repository https://github.com/imhassane/thread_rust_multiplier
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/imhassane/thread_rust_multiplier" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimhassane%2Fthread_rust_multiplier", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimhassane%2Fthread_rust_multiplier'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 681ed6d5142d27b2258c2a43643be9b218b5ebb9
[INFO] building imhassane/thread_rust_multiplier against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fimhassane%2Fthread_rust_multiplier" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/imhassane/thread_rust_multiplier on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/imhassane/thread_rust_multiplier
[INFO] finished tweaking git repo https://github.com/imhassane/thread_rust_multiplier
[INFO] tweaked toml for git repo https://github.com/imhassane/thread_rust_multiplier written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/imhassane/thread_rust_multiplier 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" "+11663cd3bfefef7d34e8f0892c250bf698049392" "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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7bf654e3c20141b6fd8dcd62e94f998062f80e09392a2cfb0a1cbc1d2eea3346
[INFO] running `Command { std: "docker" "start" "-a" "7bf654e3c20141b6fd8dcd62e94f998062f80e09392a2cfb0a1cbc1d2eea3346", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7bf654e3c20141b6fd8dcd62e94f998062f80e09392a2cfb0a1cbc1d2eea3346", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7bf654e3c20141b6fd8dcd62e94f998062f80e09392a2cfb0a1cbc1d2eea3346", kill_on_drop: false }`
[INFO] [stdout] 7bf654e3c20141b6fd8dcd62e94f998062f80e09392a2cfb0a1cbc1d2eea3346
[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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4151f86634f2531c8be2b7cde8bce4803d28b038801d1f235cb3ad1e6d871f0d
[INFO] running `Command { std: "docker" "start" "-a" "4151f86634f2531c8be2b7cde8bce4803d28b038801d1f235cb3ad1e6d871f0d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.67
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling c2-chacha v0.2.3
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling rev1 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:75:13
[INFO] [stdout]    |
[INFO] [stdout] 75 |         let mut prod = lock.lock().unwrap();
[INFO] [stdout]    |             ----^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `MutexGuard` that must be used
[INFO] [stdout]   --> src/main.rs:68:17
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if unused the Mutex will immediately unlock
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 let _ = cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `MutexGuard` that must be used
[INFO] [stdout]   --> src/main.rs:82:17
[INFO] [stdout]    |
[INFO] [stdout] 82 |                 cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if unused the Mutex will immediately unlock
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 82 |                 let _ = cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.10s
[INFO] running `Command { std: "docker" "inspect" "4151f86634f2531c8be2b7cde8bce4803d28b038801d1f235cb3ad1e6d871f0d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4151f86634f2531c8be2b7cde8bce4803d28b038801d1f235cb3ad1e6d871f0d", kill_on_drop: false }`
[INFO] [stdout] 4151f86634f2531c8be2b7cde8bce4803d28b038801d1f235cb3ad1e6d871f0d
[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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f1d35bc20c17a1a8f1bcc9beb394ee70597bf341fb4f7130026c4f59c641fd5a
[INFO] running `Command { std: "docker" "start" "-a" "f1d35bc20c17a1a8f1bcc9beb394ee70597bf341fb4f7130026c4f59c641fd5a", kill_on_drop: false }`
[INFO] [stderr]    Compiling rev1 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:75:13
[INFO] [stdout]    |
[INFO] [stdout] 75 |         let mut prod = lock.lock().unwrap();
[INFO] [stdout]    |             ----^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `MutexGuard` that must be used
[INFO] [stdout]   --> src/main.rs:68:17
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if unused the Mutex will immediately unlock
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 let _ = cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `MutexGuard` that must be used
[INFO] [stdout]   --> src/main.rs:82:17
[INFO] [stdout]    |
[INFO] [stdout] 82 |                 cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if unused the Mutex will immediately unlock
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 82 |                 let _ = cvar.wait(prod).unwrap();
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.40s
[INFO] running `Command { std: "docker" "inspect" "f1d35bc20c17a1a8f1bcc9beb394ee70597bf341fb4f7130026c4f59c641fd5a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1d35bc20c17a1a8f1bcc9beb394ee70597bf341fb4f7130026c4f59c641fd5a", kill_on_drop: false }`
[INFO] [stdout] f1d35bc20c17a1a8f1bcc9beb394ee70597bf341fb4f7130026c4f59c641fd5a