[INFO] fetching crate optbuilder 0.1.2...
[INFO] checking optbuilder-0.1.2 against try#07fecb9cf34c4979a772ba38c99d6d9144768413 for pr-87710
[INFO] extracting crate optbuilder 0.1.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate optbuilder 0.1.2 on toolchain 07fecb9cf34c4979a772ba38c99d6d9144768413
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate optbuilder 0.1.2
[INFO] finished tweaking crates.io crate optbuilder 0.1.2
[INFO] tweaked toml for crates.io crate optbuilder 0.1.2 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a78fc028f4bb448e5781daa42e0dfc38f2526de1c8878cc2e2aea56acdba323d
[INFO] running `Command { std: "docker" "start" "-a" "a78fc028f4bb448e5781daa42e0dfc38f2526de1c8878cc2e2aea56acdba323d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a78fc028f4bb448e5781daa42e0dfc38f2526de1c8878cc2e2aea56acdba323d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a78fc028f4bb448e5781daa42e0dfc38f2526de1c8878cc2e2aea56acdba323d", kill_on_drop: false }`
[INFO] [stdout] a78fc028f4bb448e5781daa42e0dfc38f2526de1c8878cc2e2aea56acdba323d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+07fecb9cf34c4979a772ba38c99d6d9144768413" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ac46dedb5a04b97dc1c2ceef29661bd2dbc22cabffb6c2e7cbb08d16f65654dd
[INFO] running `Command { std: "docker" "start" "-a" "ac46dedb5a04b97dc1c2ceef29661bd2dbc22cabffb6c2e7cbb08d16f65654dd", kill_on_drop: false }`
[INFO] [stderr]     Checking syn v1.0.75
[INFO] [stderr]     Checking optbuilder v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `a`
[INFO] [stdout]   --> tests/lib.rs:11:13
[INFO] [stdout]    |
[INFO] [stdout] 11 |             pub a: i32,
[INFO] [stdout]    |             ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `c`
[INFO] [stdout]   --> tests/lib.rs:14:13
[INFO] [stdout]    |
[INFO] [stdout] 14 |             pub c: Option<i32>,
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `a`
[INFO] [stdout]   --> tests/lib.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             pub a: i32,
[INFO] [stdout]    |             ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `b`
[INFO] [stdout]   --> tests/lib.rs:36:13
[INFO] [stdout]    |
[INFO] [stdout] 36 |             pub b: Option<i32>,
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `c`
[INFO] [stdout]   --> tests/lib.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |             pub c: Option<i32>,
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `f`
[INFO] [stdout]   --> tests/lib.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |             pub f: Option<f32>,
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.55s
[INFO] running `Command { std: "docker" "inspect" "ac46dedb5a04b97dc1c2ceef29661bd2dbc22cabffb6c2e7cbb08d16f65654dd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac46dedb5a04b97dc1c2ceef29661bd2dbc22cabffb6c2e7cbb08d16f65654dd", kill_on_drop: false }`
[INFO] [stdout] ac46dedb5a04b97dc1c2ceef29661bd2dbc22cabffb6c2e7cbb08d16f65654dd