[INFO] fetching crate blc 0.6.0...
[INFO] checking blc-0.6.0 against try#ddfd70ee3c3748e597b32f416b0d15a4f6e37685 for pr-87050
[INFO] extracting crate blc 0.6.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate blc 0.6.0 on toolchain ddfd70ee3c3748e597b32f416b0d15a4f6e37685
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ddfd70ee3c3748e597b32f416b0d15a4f6e37685" "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-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ddfd70ee3c3748e597b32f416b0d15a4f6e37685" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ddfd70ee3c3748e597b32f416b0d15a4f6e37685" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded lambda_calculus v2.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+ddfd70ee3c3748e597b32f416b0d15a4f6e37685" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 103930f288e6ded51f7adf50c446d356b91c3245f87bfdd7af5ae10381d76176
[INFO] running `Command { std: "docker" "start" "-a" "103930f288e6ded51f7adf50c446d356b91c3245f87bfdd7af5ae10381d76176", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "103930f288e6ded51f7adf50c446d356b91c3245f87bfdd7af5ae10381d76176", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "103930f288e6ded51f7adf50c446d356b91c3245f87bfdd7af5ae10381d76176", kill_on_drop: false }`
[INFO] [stdout] 103930f288e6ded51f7adf50c446d356b91c3245f87bfdd7af5ae10381d76176
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+ddfd70ee3c3748e597b32f416b0d15a4f6e37685" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1e71f8702b83ff01379d16ae641cc1d80f51ef41a6ce3b09c94c3fb5aab38f72
[INFO] running `Command { std: "docker" "start" "-a" "1e71f8702b83ff01379d16ae641cc1d80f51ef41a6ce3b09c94c3fb5aab38f72", kill_on_drop: false }`
[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: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[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: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.74s
[INFO] running `Command { std: "docker" "inspect" "1e71f8702b83ff01379d16ae641cc1d80f51ef41a6ce3b09c94c3fb5aab38f72", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e71f8702b83ff01379d16ae641cc1d80f51ef41a6ce3b09c94c3fb5aab38f72", kill_on_drop: false }`
[INFO] [stdout] 1e71f8702b83ff01379d16ae641cc1d80f51ef41a6ce3b09c94c3fb5aab38f72