[INFO] fetching crate piscina 0.2.1...
[INFO] checking piscina-0.2.1 against try#c387b04bf028733cd561d62128c8a5eee4bc1458+rustflags=-Dtail_expr_drop_order for pr-130930
[INFO] extracting crate piscina 0.2.1 into /workspace/builds/worker-0-tc2/source
[INFO] validating manifest of crates.io crate piscina 0.2.1 on toolchain c387b04bf028733cd561d62128c8a5eee4bc1458
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate piscina 0.2.1
[INFO] finished tweaking crates.io crate piscina 0.2.1
[INFO] tweaked toml for crates.io crate piscina 0.2.1 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 26 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:6252d7ea7fb8caaf7af6d800c5fb250a9cd862b9a7f9508afb3c54fa7fe1102e" "/opt/rustwide/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 13f41c66814962bac51ce59e915a9ad640098f57d1c4d489b6c1865ebd550d28
[INFO] running `Command { std: "docker" "start" "-a" "13f41c66814962bac51ce59e915a9ad640098f57d1c4d489b6c1865ebd550d28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "13f41c66814962bac51ce59e915a9ad640098f57d1c4d489b6c1865ebd550d28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "13f41c66814962bac51ce59e915a9ad640098f57d1c4d489b6c1865ebd550d28", kill_on_drop: false }`
[INFO] [stdout] 13f41c66814962bac51ce59e915a9ad640098f57d1c4d489b6c1865ebd550d28
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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 -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@sha256:6252d7ea7fb8caaf7af6d800c5fb250a9cd862b9a7f9508afb3c54fa7fe1102e" "/opt/rustwide/cargo-home/bin/cargo" "+c387b04bf028733cd561d62128c8a5eee4bc1458" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b3f63cef6304a1eb02f16a2d3ede393ab3910b30e74ed1c9ecc57f244b8a712b
[INFO] running `Command { std: "docker" "start" "-a" "b3f63cef6304a1eb02f16a2d3ede393ab3910b30e74ed1c9ecc57f244b8a712b", kill_on_drop: false }`
[INFO] [stderr]     Checking futures-channel v0.3.30
[INFO] [stderr]    Compiling syn v2.0.79
[INFO] [stderr]    Compiling futures-macro v0.3.30
[INFO] [stderr]    Compiling pin-project-internal v1.1.5
[INFO] [stderr]     Checking futures-util v0.3.30
[INFO] [stderr]     Checking pin-project v1.1.5
[INFO] [stderr]     Checking futures-executor v0.3.30
[INFO] [stderr]     Checking piscina v0.2.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking futures v0.3.30
[INFO] [stderr]     Checking futures-test v0.3.30
[INFO] [stdout] warning: method `pop` is never used
[INFO] [stdout]   --> src/internal.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub trait PoolStore {
[INFO] [stdout]    |           --------- method in this trait
[INFO] [stdout] ...
[INFO] [stdout] 10 |     fn pop(&mut self) -> Option<Self::Item>;
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `pop` is never used
[INFO] [stdout]   --> src/internal.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 6  | pub trait PoolStore {
[INFO] [stdout]    |           --------- method in this trait
[INFO] [stdout] ...
[INFO] [stdout] 10 |     fn pop(&mut self) -> Option<Self::Item>;
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: calls to `std::mem::drop` with a value that implements `Copy` does nothing
[INFO] [stdout]    --> src/pool.rs:632:9
[INFO] [stdout]     |
[INFO] [stdout] 632 |         drop(item);
[INFO] [stdout]     |         ^^^^^----^
[INFO] [stdout]     |              |
[INFO] [stdout]     |              argument has type `i32`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dropping_copy_types)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the expression or result
[INFO] [stdout]     |
[INFO] [stdout] 632 -         drop(item);
[INFO] [stdout] 632 +         let _ = item;
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: calls to `std::mem::drop` with a reference instead of an owned value does nothing
[INFO] [stdout]    --> src/priority.rs:841:9
[INFO] [stdout]     |
[INFO] [stdout] 841 |         drop(item);
[INFO] [stdout]     |         ^^^^^----^
[INFO] [stdout]     |              |
[INFO] [stdout]     |              argument has type `&str`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dropping_references)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the expression or result
[INFO] [stdout]     |
[INFO] [stdout] 841 -         drop(item);
[INFO] [stdout] 841 +         let _ = item;
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.13s
[INFO] running `Command { std: "docker" "inspect" "b3f63cef6304a1eb02f16a2d3ede393ab3910b30e74ed1c9ecc57f244b8a712b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b3f63cef6304a1eb02f16a2d3ede393ab3910b30e74ed1c9ecc57f244b8a712b", kill_on_drop: false }`
[INFO] [stdout] b3f63cef6304a1eb02f16a2d3ede393ab3910b30e74ed1c9ecc57f244b8a712b