[INFO] fetching crate serde_rec 0.1.0...
[INFO] checking serde_rec-0.1.0 against try#998b6603a58e47f42ccce7a67943234e96b6839e for pr-143170
[INFO] extracting crate serde_rec 0.1.0 into /workspace/builds/worker-1-tc2/source
[INFO] started tweaking crates.io crate serde_rec 0.1.0
[INFO] finished tweaking crates.io crate serde_rec 0.1.0
[INFO] tweaked toml for crates.io crate serde_rec 0.1.0 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate serde_rec 0.1.0 on toolchain 998b6603a58e47f42ccce7a67943234e96b6839e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "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" "+998b6603a58e47f42ccce7a67943234e96b6839e" "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 6 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8c360022a0b6c3fdb23c7aa152ea093c8c8d2545bc8bcc9441bca8cfb72f9a9d
[INFO] running `Command { std: "docker" "start" "-a" "8c360022a0b6c3fdb23c7aa152ea093c8c8d2545bc8bcc9441bca8cfb72f9a9d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8c360022a0b6c3fdb23c7aa152ea093c8c8d2545bc8bcc9441bca8cfb72f9a9d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c360022a0b6c3fdb23c7aa152ea093c8c8d2545bc8bcc9441bca8cfb72f9a9d", kill_on_drop: false }`
[INFO] [stdout] 8c360022a0b6c3fdb23c7aa152ea093c8c8d2545bc8bcc9441bca8cfb72f9a9d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+998b6603a58e47f42ccce7a67943234e96b6839e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f9d4839f50799039580f3ebdac5d85b3486dfb747193ae7d508cf2c979666b98
[INFO] running `Command { std: "docker" "start" "-a" "f9d4839f50799039580f3ebdac5d85b3486dfb747193ae7d508cf2c979666b98", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.95
[INFO] [stderr]    Compiling unicode-ident v1.0.18
[INFO] [stderr]    Compiling serde v1.0.219
[INFO] [stderr]    Compiling quote v1.0.40
[INFO] [stderr]    Compiling syn v2.0.104
[INFO] [stderr]    Compiling serde_derive v1.0.219
[INFO] [stderr]     Checking serde_rec v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `length` is never read
[INFO] [stdout]    --> src/ser.rs:227:5
[INFO] [stdout]     |
[INFO] [stdout] 224 | pub struct SerializerSeq<'a, 'b> {
[INFO] [stdout]     |            ------------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 227 |     length: usize,
[INFO] [stdout]     |     ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `SerializerSeq` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `length` is never read
[INFO] [stdout]    --> src/ser.rs:227:5
[INFO] [stdout]     |
[INFO] [stdout] 224 | pub struct SerializerSeq<'a, 'b> {
[INFO] [stdout]     |            ------------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 227 |     length: usize,
[INFO] [stdout]     |     ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `SerializerSeq` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 6.65s
[INFO] running `Command { std: "docker" "inspect" "f9d4839f50799039580f3ebdac5d85b3486dfb747193ae7d508cf2c979666b98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f9d4839f50799039580f3ebdac5d85b3486dfb747193ae7d508cf2c979666b98", kill_on_drop: false }`
[INFO] [stdout] f9d4839f50799039580f3ebdac5d85b3486dfb747193ae7d508cf2c979666b98