[INFO] fetching crate def-mod 0.5.0...
[INFO] documenting def-mod-0.5.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate def-mod 0.5.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate def-mod 0.5.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate def-mod 0.5.0
[INFO] finished tweaking crates.io crate def-mod 0.5.0
[INFO] tweaked toml for crates.io crate def-mod 0.5.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate crates.io crate def-mod 0.5.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9114ca10b9dc431d037c7f1b8a3c31f0f6851fc990ef51b77b8a5ad76dc241e8
[INFO] running `Command { std: "docker" "start" "-a" "9114ca10b9dc431d037c7f1b8a3c31f0f6851fc990ef51b77b8a5ad76dc241e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9114ca10b9dc431d037c7f1b8a3c31f0f6851fc990ef51b77b8a5ad76dc241e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9114ca10b9dc431d037c7f1b8a3c31f0f6851fc990ef51b77b8a5ad76dc241e8", kill_on_drop: false }`
[INFO] [stdout] 9114ca10b9dc431d037c7f1b8a3c31f0f6851fc990ef51b77b8a5ad76dc241e8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ad49d09709d3f66dbfd51563c5f6ef7aa6f539b99d472933a2b437f3820743bb
[INFO] running `Command { std: "docker" "start" "-a" "ad49d09709d3f66dbfd51563c5f6ef7aa6f539b99d472933a2b437f3820743bb", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.24
[INFO] [stderr]     Checking quote v0.6.10
[INFO] [stderr]     Checking syn v0.14.9
[INFO] [stderr]  Documenting def-mod v0.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> src/lib.rs:176:1
[INFO] [stdout]     |
[INFO] [stdout] 176 | #![feature(proc_macro_diagnostic)]
[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 `def-mod`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type proc-macro --crate-name def_mod src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-100c48a5f1d2140a.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-8fdd8abc2716c476.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-c853d5e52089fea0.rmeta --extern proc_macro --cap-lints=warn --crate-version 0.5.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "ad49d09709d3f66dbfd51563c5f6ef7aa6f539b99d472933a2b437f3820743bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ad49d09709d3f66dbfd51563c5f6ef7aa6f539b99d472933a2b437f3820743bb", kill_on_drop: false }`
[INFO] [stdout] ad49d09709d3f66dbfd51563c5f6ef7aa6f539b99d472933a2b437f3820743bb
