[INFO] fetching crate phlow 1.5.0...
[INFO] documenting phlow-1.5.0 against 1.75.0 for beta-1.76-rustdoc-1
[INFO] extracting crate phlow 1.5.0 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate phlow 1.5.0 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate phlow 1.5.0
[INFO] finished tweaking crates.io crate phlow 1.5.0
[INFO] tweaked toml for crates.io crate phlow 1.5.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "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" "+1.75.0" "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 blob-uuid v0.5.0
[INFO] [stderr]   Downloaded unique_id v0.1.5
[INFO] [stderr]   Downloaded phlow-derive v1.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 96541a5e74f4d19c6dd2ad7959d82bdd1a11158ab98ad970f7328d12ffac2a38
[INFO] running `Command { std: "docker" "start" "-a" "96541a5e74f4d19c6dd2ad7959d82bdd1a11158ab98ad970f7328d12ffac2a38", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "96541a5e74f4d19c6dd2ad7959d82bdd1a11158ab98ad970f7328d12ffac2a38", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "96541a5e74f4d19c6dd2ad7959d82bdd1a11158ab98ad970f7328d12ffac2a38", kill_on_drop: false }`
[INFO] [stdout] 96541a5e74f4d19c6dd2ad7959d82bdd1a11158ab98ad970f7328d12ffac2a38
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+1.75.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e98c3f5b999c4a36f16c66ad42837d60cb35e3ff28529920a837b8eebd854d6b
[INFO] running `Command { std: "docker" "start" "-a" "e98c3f5b999c4a36f16c66ad42837d60cb35e3ff28529920a837b8eebd854d6b", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.76
[INFO] [stderr]    Compiling unicode-ident v1.0.12
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling libc v0.2.151
[INFO] [stderr]    Compiling parking_lot_core v0.9.9
[INFO] [stderr]     Checking smallvec v1.11.2
[INFO] [stderr]     Checking scopeguard v1.2.0
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking log v0.4.20
[INFO] [stderr]    Compiling lock_api v0.4.11
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling rust-format v0.3.4
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]     Checking parking_lot v0.12.1
[INFO] [stderr]    Compiling phlow-derive v1.4.0
[INFO] [stderr]  Documenting phlow v1.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:4:35
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "printing", feature(specialization))]
[INFO] [stdout]   |                                   ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 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 `phlow`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/1.75.0-x86_64-unknown-linux-gnu/bin/rustdoc --edition=2021 --crate-type lib --crate-name phlow src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="phlow-derive"' --cfg 'feature="printing"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=b2d18e5b75c30c91 -L dependency=/opt/rustwide/target/debug/deps --extern log=/opt/rustwide/target/debug/deps/liblog-91e42ebaf8a62e54.rmeta --extern parking_lot=/opt/rustwide/target/debug/deps/libparking_lot-d88da3e34f4b746e.rmeta --extern phlow_derive=/opt/rustwide/target/debug/deps/libphlow_derive-cf62a73648bab126.so --cap-lints=warn --crate-version 1.5.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "e98c3f5b999c4a36f16c66ad42837d60cb35e3ff28529920a837b8eebd854d6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e98c3f5b999c4a36f16c66ad42837d60cb35e3ff28529920a837b8eebd854d6b", kill_on_drop: false }`
[INFO] [stdout] e98c3f5b999c4a36f16c66ad42837d60cb35e3ff28529920a837b8eebd854d6b
