[INFO] fetching crate docbot-derive 0.3.0-alpha.2...
[INFO] documenting docbot-derive-0.3.0-alpha.2 against 1.76.0 for beta-1.77-rustdoc-1
[INFO] extracting crate docbot-derive 0.3.0-alpha.2 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate docbot-derive 0.3.0-alpha.2 on toolchain 1.76.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate docbot-derive 0.3.0-alpha.2
[INFO] finished tweaking crates.io crate docbot-derive 0.3.0-alpha.2
[INFO] tweaked toml for crates.io crate docbot-derive 0.3.0-alpha.2 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9c2d97aba9b5432ae7ce4b8ddba5009f11ccf32d95ba02672be08e2ed0d31aa5
[INFO] running `Command { std: "docker" "start" "-a" "9c2d97aba9b5432ae7ce4b8ddba5009f11ccf32d95ba02672be08e2ed0d31aa5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9c2d97aba9b5432ae7ce4b8ddba5009f11ccf32d95ba02672be08e2ed0d31aa5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9c2d97aba9b5432ae7ce4b8ddba5009f11ccf32d95ba02672be08e2ed0d31aa5", kill_on_drop: false }`
[INFO] [stdout] 9c2d97aba9b5432ae7ce4b8ddba5009f11ccf32d95ba02672be08e2ed0d31aa5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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=warn" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fde915bed52b1474dd7f88b94c088f8a625bf6ecca916f99d1085f437a9f9f79
[INFO] running `Command { std: "docker" "start" "-a" "fde915bed52b1474dd7f88b94c088f8a625bf6ecca916f99d1085f437a9f9f79", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]     Checking memchr v2.7.1
[INFO] [stderr]     Checking regex-syntax v0.8.2
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling anyhow v1.0.79
[INFO] [stderr]     Checking quote v1.0.35
[INFO] [stderr]     Checking aho-corasick v1.1.2
[INFO] [stderr]     Checking syn v1.0.109
[INFO] [stderr]     Checking regex-automata v0.4.5
[INFO] [stderr]     Checking regex v1.10.3
[INFO] [stderr]  Documenting docbot-derive v0.3.0-alpha.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> lib.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(proc_macro_diagnostic)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `docbot-derive`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/1.76.0-x86_64-unknown-linux-gnu/bin/rustdoc --edition=2021 --crate-type proc-macro --crate-name docbot_derive lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=92b0ed2d17228e61 -L dependency=/opt/rustwide/target/debug/deps --extern anyhow=/opt/rustwide/target/debug/deps/libanyhow-a43e27e027e19cdb.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-54059fb39f474b94.rmeta --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-1bc556be54688c37.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-44762e16f83d10ff.rmeta --extern regex=/opt/rustwide/target/debug/deps/libregex-b5a1473c50deffba.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-c5b78201a2fb072c.rmeta --extern proc_macro --cap-lints=warn --crate-version 0.3.0-alpha.2` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "fde915bed52b1474dd7f88b94c088f8a625bf6ecca916f99d1085f437a9f9f79", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fde915bed52b1474dd7f88b94c088f8a625bf6ecca916f99d1085f437a9f9f79", kill_on_drop: false }`
[INFO] [stdout] fde915bed52b1474dd7f88b94c088f8a625bf6ecca916f99d1085f437a9f9f79
