[INFO] fetching crate blc 0.6.0...
[INFO] checking blc-0.6.0 against try#7014e13d5becc920d4bea3cd87942c8a13d359bf+rustflags=-Dtail_expr_drop_order for pr-129864
[INFO] extracting crate blc 0.6.0 into /workspace/builds/worker-6-tc2/source
[INFO] validating manifest of crates.io crate blc 0.6.0 on toolchain 7014e13d5becc920d4bea3cd87942c8a13d359bf
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate blc 0.6.0
[INFO] finished tweaking crates.io crate blc 0.6.0
[INFO] tweaked toml for crates.io crate blc 0.6.0 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" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "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] [stderr]       Adding lambda_calculus v2.2.0 (available: v3.3.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition while the latest is 2021
[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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ce22b27f88b8b09dc54b9092700cc9c23e688847ca11960f1491da66f16f5f53
[INFO] running `Command { std: "docker" "start" "-a" "ce22b27f88b8b09dc54b9092700cc9c23e688847ca11960f1491da66f16f5f53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ce22b27f88b8b09dc54b9092700cc9c23e688847ca11960f1491da66f16f5f53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce22b27f88b8b09dc54b9092700cc9c23e688847ca11960f1491da66f16f5f53", kill_on_drop: false }`
[INFO] [stdout] ce22b27f88b8b09dc54b9092700cc9c23e688847ca11960f1491da66f16f5f53
[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 -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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+7014e13d5becc920d4bea3cd87942c8a13d359bf" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bee2519397e4aa698bd96adf39c77be7d5169e4b46b6e05978ed89d05381cea2
[INFO] running `Command { std: "docker" "start" "-a" "bee2519397e4aa698bd96adf39c77be7d5169e4b46b6e05978ed89d05381cea2", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition while the latest is 2021
[INFO] [stderr]     Checking lambda_calculus v2.2.0
[INFO] [stderr]     Checking blc v0.6.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `#[macro_use]` import
[INFO] [stdout]   --> src/lib.rs:42:1
[INFO] [stdout]    |
[INFO] [stdout] 42 | #[macro_use]
[INFO] [stdout]    | ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/pair_list.rs:112:5
[INFO] [stdout]     |
[INFO] [stdout] 112 |     mem::replace(term, tail.clone()); // replace term with tail
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 112 |     let _ = mem::replace(term, tail.clone()); // replace term with tail
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/pair_list.rs:112:5
[INFO] [stdout]     |
[INFO] [stdout] 112 |     mem::replace(term, tail.clone()); // replace term with tail
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 112 |     let _ = mem::replace(term, tail.clone()); // replace term with tail
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.77s
[INFO] running `Command { std: "docker" "inspect" "bee2519397e4aa698bd96adf39c77be7d5169e4b46b6e05978ed89d05381cea2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bee2519397e4aa698bd96adf39c77be7d5169e4b46b6e05978ed89d05381cea2", kill_on_drop: false }`
[INFO] [stdout] bee2519397e4aa698bd96adf39c77be7d5169e4b46b6e05978ed89d05381cea2