[INFO] fetching crate syn 1.0.39...
[INFO] documenting syn-1.0.39 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate syn 1.0.39 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate syn 1.0.39 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate syn 1.0.39
[INFO] finished tweaking crates.io crate syn 1.0.39
[INFO] tweaked toml for crates.io crate syn 1.0.39 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded syn-test-suite v0.0.0+test
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f5bacafba0e1621252cf137598fdba2ec34043ba0daa92cf1cbad4654423ef41
[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" "f5bacafba0e1621252cf137598fdba2ec34043ba0daa92cf1cbad4654423ef41", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f5bacafba0e1621252cf137598fdba2ec34043ba0daa92cf1cbad4654423ef41", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f5bacafba0e1621252cf137598fdba2ec34043ba0daa92cf1cbad4654423ef41", kill_on_drop: false }`
[INFO] [stdout] f5bacafba0e1621252cf137598fdba2ec34043ba0daa92cf1cbad4654423ef41
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "RUSTDOCFLAGS=--cap-lints=warn" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b2b0d589ef18b549a914c05e91f83dbbabac2578be869d3993b6b4449d0ed2b3
[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" "b2b0d589ef18b549a914c05e91f83dbbabac2578be869d3993b6b4449d0ed2b3", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.39 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting syn v1.0.39 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.80s
[INFO] running `Command { std: "docker" "inspect" "b2b0d589ef18b549a914c05e91f83dbbabac2578be869d3993b6b4449d0ed2b3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2b0d589ef18b549a914c05e91f83dbbabac2578be869d3993b6b4449d0ed2b3", kill_on_drop: false }`
[INFO] [stdout] b2b0d589ef18b549a914c05e91f83dbbabac2578be869d3993b6b4449d0ed2b3