[INFO] fetching crate serde-object 0.0.0-alpha.0...
[INFO] checking serde-object-0.0.0-alpha.0 against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] extracting crate serde-object 0.0.0-alpha.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate serde-object 0.0.0-alpha.0 on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate serde-object 0.0.0-alpha.0
[INFO] finished tweaking crates.io crate serde-object 0.0.0-alpha.0
[INFO] tweaked toml for crates.io crate serde-object 0.0.0-alpha.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 51e7f3dd422614ed4f0f8deecaada39dee520ce73c2a2359bfd7e8ce804158be
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "51e7f3dd422614ed4f0f8deecaada39dee520ce73c2a2359bfd7e8ce804158be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "51e7f3dd422614ed4f0f8deecaada39dee520ce73c2a2359bfd7e8ce804158be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51e7f3dd422614ed4f0f8deecaada39dee520ce73c2a2359bfd7e8ce804158be", kill_on_drop: false }`
[INFO] [stdout] 51e7f3dd422614ed4f0f8deecaada39dee520ce73c2a2359bfd7e8ce804158be
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 274b5b59cd675db94bae4b9d5b6808552426eee59425e5207efe2900217bf028
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "274b5b59cd675db94bae4b9d5b6808552426eee59425e5207efe2900217bf028", kill_on_drop: false }`
[INFO] [stderr]     Checking wyz v0.2.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling try_match_inner v0.2.0
[INFO] [stderr]     Checking try_match v0.2.2
[INFO] [stderr]     Checking serde-object v0.0.0-alpha.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]     --> src/lib.rs:1006:31
[INFO] [stdout]      |
[INFO] [stdout] 1006 |     fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
[INFO] [stdout]      |                               ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fields`
[INFO] [stdout]     --> src/lib.rs:1018:9
[INFO] [stdout]      |
[INFO] [stdout] 1018 |         fields: &'static [&'static str],
[INFO] [stdout]      |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_fields`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]     --> src/lib.rs:1006:31
[INFO] [stdout]      |
[INFO] [stdout] 1006 |     fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
[INFO] [stdout]      |                               ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fields`
[INFO] [stdout]     --> src/lib.rs:1018:9
[INFO] [stdout]      |
[INFO] [stdout] 1018 |         fields: &'static [&'static str],
[INFO] [stdout]      |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_fields`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 19.17s
[INFO] running `Command { std: "docker" "inspect" "274b5b59cd675db94bae4b9d5b6808552426eee59425e5207efe2900217bf028", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "274b5b59cd675db94bae4b9d5b6808552426eee59425e5207efe2900217bf028", kill_on_drop: false }`
[INFO] [stdout] 274b5b59cd675db94bae4b9d5b6808552426eee59425e5207efe2900217bf028