[INFO] fetching crate apt-cache 0.1.3...
[INFO] documenting apt-cache-0.1.3 against 1.75.0 for beta-1.76-rustdoc-1
[INFO] extracting crate apt-cache 0.1.3 into /workspace/builds/worker-5-tc1/source
[INFO] validating manifest of crates.io crate apt-cache 0.1.3 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 apt-cache 0.1.3
[INFO] finished tweaking crates.io crate apt-cache 0.1.3
[INFO] tweaked toml for crates.io crate apt-cache 0.1.3 written to /workspace/builds/worker-5-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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] d700108ebe338eb2ea1ff16b48910c881815aef446defb2a3ebadbb8ed2960fe
[INFO] running `Command { std: "docker" "start" "-a" "d700108ebe338eb2ea1ff16b48910c881815aef446defb2a3ebadbb8ed2960fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d700108ebe338eb2ea1ff16b48910c881815aef446defb2a3ebadbb8ed2960fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d700108ebe338eb2ea1ff16b48910c881815aef446defb2a3ebadbb8ed2960fe", kill_on_drop: false }`
[INFO] [stdout] d700108ebe338eb2ea1ff16b48910c881815aef446defb2a3ebadbb8ed2960fe
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 6c06fc53bdec8e5e57c022c62401e3f84fc4988fbe199daa68197df68decd588
[INFO] running `Command { std: "docker" "start" "-a" "6c06fc53bdec8e5e57c022c62401e3f84fc4988fbe199daa68197df68decd588", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.76
[INFO] [stderr]    Compiling unicode-ident v1.0.12
[INFO] [stderr]    Compiling serde v1.0.195
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling serde_derive v1.0.195
[INFO] [stderr]  Documenting apt-cache v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:16:12
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(str_strip)]
[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 `apt-cache`
[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=2018 --crate-type lib --crate-name apt_cache src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=97b5f5d6952f871a -L dependency=/opt/rustwide/target/debug/deps --extern serde=/opt/rustwide/target/debug/deps/libserde-319bf41ec1876518.rmeta --cap-lints=warn --crate-version 0.1.3` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "6c06fc53bdec8e5e57c022c62401e3f84fc4988fbe199daa68197df68decd588", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6c06fc53bdec8e5e57c022c62401e3f84fc4988fbe199daa68197df68decd588", kill_on_drop: false }`
[INFO] [stdout] 6c06fc53bdec8e5e57c022c62401e3f84fc4988fbe199daa68197df68decd588
