[INFO] fetching crate label-macros 0.6.0...
[INFO] documenting label-macros-0.6.0 against beta-2021-08-01 for beta-1.55-rustdoc-1
[INFO] extracting crate label-macros 0.6.0 into /workspace/builds/worker-62/source
[INFO] validating manifest of crates.io crate label-macros 0.6.0 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate label-macros 0.6.0
[INFO] finished tweaking crates.io crate label-macros 0.6.0
[INFO] tweaked toml for crates.io crate label-macros 0.6.0 written to /workspace/builds/worker-62/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "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-62/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/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" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 75c69d8d9a028d033eac253566ed9b0aa00d0d15721252d8a3bddc664b9bd3f0
[INFO] running `Command { std: "docker" "start" "-a" "75c69d8d9a028d033eac253566ed9b0aa00d0d15721252d8a3bddc664b9bd3f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "75c69d8d9a028d033eac253566ed9b0aa00d0d15721252d8a3bddc664b9bd3f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "75c69d8d9a028d033eac253566ed9b0aa00d0d15721252d8a3bddc664b9bd3f0", kill_on_drop: false }`
[INFO] [stdout] 75c69d8d9a028d033eac253566ed9b0aa00d0d15721252d8a3bddc664b9bd3f0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/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" "+beta-2021-08-01" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 97096b7afb400d477c7cdc1a5dc8f98cbc849b4ff42d13a32aa302a58bab347e
[INFO] running `Command { std: "docker" "start" "-a" "97096b7afb400d477c7cdc1a5dc8f98cbc849b4ff42d13a32aa302a58bab347e", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]     Checking unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]     Checking quote v1.0.9
[INFO] [stderr]  Documenting label-macros v0.6.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `syn::export`
[INFO] [stdout]   --> src/lib.rs:14:10
[INFO] [stdout]    |
[INFO] [stdout] 14 | use syn::export::ToTokens;
[INFO] [stdout]    |          ^^^^^^ could not find `export` in `syn`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: could not find `export` in `syn`
[INFO] [stdout]   --> src/lib.rs:78:43
[INFO] [stdout]    |
[INFO] [stdout] 78 |     fn to_tokens(&self, tokens: &mut syn::export::TokenStream2) {
[INFO] [stdout]    |                                           ^^^^^^ could not find `export` in `syn`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(proc_macro_span)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0433, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `label-macros`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type proc-macro --crate-name label_macros src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern quote=/opt/rustwide/target/debug/deps/libquote-4376c41958740794.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-057fd28619885c6f.rmeta --extern proc_macro --cap-lints=warn --crate-version 0.6.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "97096b7afb400d477c7cdc1a5dc8f98cbc849b4ff42d13a32aa302a58bab347e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "97096b7afb400d477c7cdc1a5dc8f98cbc849b4ff42d13a32aa302a58bab347e", kill_on_drop: false }`
[INFO] [stdout] 97096b7afb400d477c7cdc1a5dc8f98cbc849b4ff42d13a32aa302a58bab347e
