[INFO] fetching crate plex 0.2.5...
[INFO] documenting plex-0.2.5 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate plex 0.2.5 into /workspace/builds/worker-33/source
[INFO] validating manifest of crates.io crate plex 0.2.5 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 plex 0.2.5
[INFO] finished tweaking crates.io crate plex 0.2.5
[INFO] tweaked toml for crates.io crate plex 0.2.5 written to /workspace/builds/worker-33/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] [stderr]     Blocking waiting for file lock on package cache
[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]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded redfa v0.0.2
[INFO] [stderr]   Downloaded vec_map v0.6.0
[INFO] [stderr]   Downloaded lalr v0.0.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/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] 0d3542c4b1d8e28432855b6831522fdae15c2278db5c5b94309a8ac1c98abb63
[INFO] running `Command { std: "docker" "start" "-a" "0d3542c4b1d8e28432855b6831522fdae15c2278db5c5b94309a8ac1c98abb63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0d3542c4b1d8e28432855b6831522fdae15c2278db5c5b94309a8ac1c98abb63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d3542c4b1d8e28432855b6831522fdae15c2278db5c5b94309a8ac1c98abb63", kill_on_drop: false }`
[INFO] [stdout] 0d3542c4b1d8e28432855b6831522fdae15c2278db5c5b94309a8ac1c98abb63
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/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] [stdout] 43eddf049e883f11b5ef0bc9c4da7c39996a0386d562b5d8f001b5aa990389ef
[INFO] running `Command { std: "docker" "start" "-a" "43eddf049e883f11b5ef0bc9c4da7c39996a0386d562b5d8f001b5aa990389ef", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]     Checking unicode-xid v0.1.0
[INFO] [stderr]     Checking bit-vec v0.4.4
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking vec_map v0.6.0
[INFO] [stderr]     Checking lalr v0.0.2
[INFO] [stderr]     Checking bit-set v0.4.0
[INFO] [stderr]     Checking redfa v0.0.2
[INFO] [stderr]     Checking quote v0.6.13
[INFO] [stderr]  Documenting plex v0.2.5 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(proc_macro_diagnostic)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(proc_macro_span)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^
[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 `plex`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type proc-macro --crate-name plex src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="lalr"' --cfg 'feature="lexer"' --cfg 'feature="parser"' --cfg 'feature="redfa"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=f39e2a1105926848 -L dependency=/opt/rustwide/target/debug/deps --extern lalr=/opt/rustwide/target/debug/deps/liblalr-7995b326f50042c7.rmeta --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-a022d4572177b1a5.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-e7b681e7b0e1f228.rmeta --extern redfa=/opt/rustwide/target/debug/deps/libredfa-85a8015908e4c812.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-381110a0a5dbf6af.rmeta --extern proc_macro --cap-lints=warn --crate-version 0.2.5` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "43eddf049e883f11b5ef0bc9c4da7c39996a0386d562b5d8f001b5aa990389ef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43eddf049e883f11b5ef0bc9c4da7c39996a0386d562b5d8f001b5aa990389ef", kill_on_drop: false }`
[INFO] [stdout] 43eddf049e883f11b5ef0bc9c4da7c39996a0386d562b5d8f001b5aa990389ef