[INFO] cloning repository https://github.com/grajnikanth/rust_book_exs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/grajnikanth/rust_book_exs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgrajnikanth%2Frust_book_exs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgrajnikanth%2Frust_book_exs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a21fa10a147af0898615d7706e29a64e9691149c
[INFO] documenting grajnikanth/rust_book_exs against beta-2023-04-20 for beta-1.70-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgrajnikanth%2Frust_book_exs" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/grajnikanth/rust_book_exs on toolchain beta-2023-04-20
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2023-04-20" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/grajnikanth/rust_book_exs
[INFO] finished tweaking git repo https://github.com/grajnikanth/rust_book_exs
[INFO] tweaked toml for git repo https://github.com/grajnikanth/rust_book_exs written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/grajnikanth/rust_book_exs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2023-04-20" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2023-04-20" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a2d0abe3a151e3412730249e2fc74b97e1b83d9acf85351f24585909a1930809
[INFO] running `Command { std: "docker" "start" "-a" "a2d0abe3a151e3412730249e2fc74b97e1b83d9acf85351f24585909a1930809", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a2d0abe3a151e3412730249e2fc74b97e1b83d9acf85351f24585909a1930809", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a2d0abe3a151e3412730249e2fc74b97e1b83d9acf85351f24585909a1930809", kill_on_drop: false }`
[INFO] [stdout] a2d0abe3a151e3412730249e2fc74b97e1b83d9acf85351f24585909a1930809
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2023-04-20" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 648d3cc47d3d04e4483af9447bb25d13d97d06011777532eea4b1f39aea103a2
[INFO] running `Command { std: "docker" "start" "-a" "648d3cc47d3d04e4483af9447bb25d13d97d06011777532eea4b1f39aea103a2", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_book_exs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting rust_book_exs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]   --> src/lib.rs:58:8
[INFO] [stdout]    |
[INFO] [stdout] 58 | struct Pair<T> {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/lib.rs:64:8
[INFO] [stdout]    |
[INFO] [stdout] 63 | impl<T> Pair<T> {
[INFO] [stdout]    | --------------- associated function in this implementation
[INFO] [stdout] 64 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `compare_display` is never used
[INFO] [stdout]   --> src/lib.rs:72:8
[INFO] [stdout]    |
[INFO] [stdout] 69 | impl<T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]    | ------------------------------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 72 |     fn compare_display(&self) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0053]: method `return_number` has an incompatible type for trait
[INFO] [stdout]   --> src/bin/81_int_mutable_usecase.rs:32:22
[INFO] [stdout]    |
[INFO] [stdout] 32 |     fn return_number(&mut self) -> u32 {
[INFO] [stdout]    |                      ^^^^^^^^^
[INFO] [stdout]    |                      |
[INFO] [stdout]    |                      types differ in mutability
[INFO] [stdout]    |                      help: change the self-receiver type to match the trait: `self: &Book`
[INFO] [stdout]    |
[INFO] [stdout] note: type in trait
[INFO] [stdout]   --> src/bin/81_int_mutable_usecase.rs:17:22
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn return_number(&self) -> u32;
[INFO] [stdout]    |                      ^^^^^
[INFO] [stdout]    = note: expected signature `fn(&Book) -> _`
[INFO] [stdout]               found signature `fn(&mut Book) -> _`
[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 E0053`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `rust_book_exs`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2021 --crate-type bin --crate-name 81_int_mutable_usecase src/bin/81_int_mutable_usecase.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items '-Arustdoc::private-intra-doc-links' -C metadata=966600a5da90e785 -L dependency=/opt/rustwide/target/debug/deps --extern rust_book_exs=/opt/rustwide/target/debug/deps/librust_book_exs-c5db50a4bfc6d0b4.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "648d3cc47d3d04e4483af9447bb25d13d97d06011777532eea4b1f39aea103a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "648d3cc47d3d04e4483af9447bb25d13d97d06011777532eea4b1f39aea103a2", kill_on_drop: false }`
[INFO] [stdout] 648d3cc47d3d04e4483af9447bb25d13d97d06011777532eea4b1f39aea103a2
