[INFO] fetching crate proc-macro-kwargs 0.1.5...
[INFO] documenting proc-macro-kwargs-0.1.5 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate proc-macro-kwargs 0.1.5 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate proc-macro-kwargs 0.1.5 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate proc-macro-kwargs 0.1.5
[INFO] finished tweaking crates.io crate proc-macro-kwargs 0.1.5
[INFO] tweaked toml for crates.io crate proc-macro-kwargs 0.1.5 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded proc-macro-kwargs-derive v0.1.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d2d5947c2c464b18fa657a97d730dbfc183531defe06fa9405088728e3f75776
[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" "d2d5947c2c464b18fa657a97d730dbfc183531defe06fa9405088728e3f75776", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d2d5947c2c464b18fa657a97d730dbfc183531defe06fa9405088728e3f75776", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d2d5947c2c464b18fa657a97d730dbfc183531defe06fa9405088728e3f75776", kill_on_drop: false }`
[INFO] [stdout] d2d5947c2c464b18fa657a97d730dbfc183531defe06fa9405088728e3f75776
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] cef3561732923b7e7cbe745da61a31abffdf4eedbfc9dcb52308f4bcf37b854f
[INFO] running `Command { std: "docker" "start" "-a" "cef3561732923b7e7cbe745da61a31abffdf4eedbfc9dcb52308f4bcf37b854f", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling unicode-ident v1.0.0
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]     Checking quote v1.0.18
[INFO] [stderr]    Compiling proc-macro-kwargs-derive v0.1.5
[INFO] [stderr]  Documenting proc-macro-kwargs v0.1.5 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `proc-macro-kwargs`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name proc_macro_kwargs src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=bcdaaf095b6a6af1 -L dependency=/opt/rustwide/target/debug/deps --extern indexmap=/opt/rustwide/target/debug/deps/libindexmap-33ef8bea342ba240.rmeta --extern proc_macro_kwargs_derive=/opt/rustwide/target/debug/deps/libproc_macro_kwargs_derive-72356d25dd827a76.so --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-c1d3bfa6658bd3cb.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-5e860005d80c271d.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-dc001e36810ebbc6.rmeta --cap-lints=warn --crate-version 0.1.5` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "cef3561732923b7e7cbe745da61a31abffdf4eedbfc9dcb52308f4bcf37b854f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cef3561732923b7e7cbe745da61a31abffdf4eedbfc9dcb52308f4bcf37b854f", kill_on_drop: false }`
[INFO] [stdout] cef3561732923b7e7cbe745da61a31abffdf4eedbfc9dcb52308f4bcf37b854f