[INFO] fetching crate serde-html 0.0.1...
[INFO] documenting serde-html-0.0.1 against 1.75.0 for beta-1.76-rustdoc-1
[INFO] extracting crate serde-html 0.0.1 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate serde-html 0.0.1 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 serde-html 0.0.1
[INFO] finished tweaking crates.io crate serde-html 0.0.1
[INFO] tweaked toml for crates.io crate serde-html 0.0.1 written to /workspace/builds/worker-0-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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 64a18555a320351bb91475bd86990b3ca9e30a1484039b3d79274ef0b5e796ee
[INFO] running `Command { std: "docker" "start" "-a" "64a18555a320351bb91475bd86990b3ca9e30a1484039b3d79274ef0b5e796ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "64a18555a320351bb91475bd86990b3ca9e30a1484039b3d79274ef0b5e796ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "64a18555a320351bb91475bd86990b3ca9e30a1484039b3d79274ef0b5e796ee", kill_on_drop: false }`
[INFO] [stdout] 64a18555a320351bb91475bd86990b3ca9e30a1484039b3d79274ef0b5e796ee
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] fb96e0c023cb953e548c0321c20dcaff83d0c3d0f1488bd84174b34428ec183d
[INFO] running `Command { std: "docker" "start" "-a" "fb96e0c023cb953e548c0321c20dcaff83d0c3d0f1488bd84174b34428ec183d", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.76
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling serde_derive v1.0.195
[INFO] [stderr]     Checking serde v1.0.195
[INFO] [stderr]  Documenting serde-html v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(return_position_impl_trait_in_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `return_position_impl_trait_in_trait` has been stable since `1.75.0` and no longer requires an attribute to enable
[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 `serde-html`
[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 serde_html src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=a01e98b588d445b3 -L dependency=/opt/rustwide/target/debug/deps --extern indexmap=/opt/rustwide/target/debug/deps/libindexmap-d856f3e7230da7bc.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-319bf41ec1876518.rmeta --cap-lints=warn --crate-version 0.0.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "fb96e0c023cb953e548c0321c20dcaff83d0c3d0f1488bd84174b34428ec183d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb96e0c023cb953e548c0321c20dcaff83d0c3d0f1488bd84174b34428ec183d", kill_on_drop: false }`
[INFO] [stdout] fb96e0c023cb953e548c0321c20dcaff83d0c3d0f1488bd84174b34428ec183d
