[INFO] fetching crate solitaire-core 0.0.1...
[INFO] documenting solitaire-core-0.0.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate solitaire-core 0.0.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate solitaire-core 0.0.1 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate solitaire-core 0.0.1
[INFO] finished tweaking crates.io crate solitaire-core 0.0.1
[INFO] tweaked toml for crates.io crate solitaire-core 0.0.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "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-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2727ba222729e99539365a31b6b78ebf0aab178624941e7478314a3e38559941
[INFO] running `Command { std: "docker" "start" "-a" "2727ba222729e99539365a31b6b78ebf0aab178624941e7478314a3e38559941", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2727ba222729e99539365a31b6b78ebf0aab178624941e7478314a3e38559941", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2727ba222729e99539365a31b6b78ebf0aab178624941e7478314a3e38559941", kill_on_drop: false }`
[INFO] [stdout] 2727ba222729e99539365a31b6b78ebf0aab178624941e7478314a3e38559941
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 247e782c9b3e076bd7f0a00642ee4e5bd6a771899832810d2e2030ee05b63681
[INFO] running `Command { std: "docker" "start" "-a" "247e782c9b3e076bd7f0a00642ee4e5bd6a771899832810d2e2030ee05b63681", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling unicode-ident v1.0.0
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling pkg-config v0.3.25
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling anyhow v1.0.57
[INFO] [stderr]    Compiling convert_case v0.4.0
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking ryu v1.0.10
[INFO] [stderr]    Compiling form_urlencoded v1.0.1
[INFO] [stderr]    Compiling idna v0.2.3
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling url v2.2.2
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]    Compiling jobserver v0.1.24
[INFO] [stderr]    Compiling time v0.1.43
[INFO] [stderr]     Checking getrandom v0.2.6
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]    Compiling libz-sys v1.1.8
[INFO] [stderr]    Compiling libgit2-sys v0.9.2
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling serde_derive v1.0.137
[INFO] [stderr]    Compiling derive_more v0.99.17
[INFO] [stderr]    Compiling git2 v0.10.2
[INFO] [stderr]    Compiling toml v0.5.9
[INFO] [stderr]     Checking bincode v1.3.3
[INFO] [stderr]     Checking uuid v0.8.2
[INFO] [stderr]     Checking serde_json v1.0.81
[INFO] [stderr]    Compiling built v0.3.2
[INFO] [stderr]    Compiling solitaire-core v0.0.1 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting solitaire-core 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:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(option_expect_none)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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(fn_traits)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(unboxed_closures)]
[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] [stderr] error: could not document `solitaire-core`
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name solitaire_core src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=bcb3578c91ff553e -L dependency=/opt/rustwide/target/debug/deps --extern anyhow=/opt/rustwide/target/debug/deps/libanyhow-a2ad8fa07e0781ab.rmeta --extern bincode=/opt/rustwide/target/debug/deps/libbincode-b4845b96b0486b0f.rmeta --extern derive_more=/opt/rustwide/target/debug/deps/libderive_more-ae1f45806efe266e.so --extern serde=/opt/rustwide/target/debug/deps/libserde-b3b87f46a79345b8.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-e8cd05653383fb34.rmeta --extern uuid=/opt/rustwide/target/debug/deps/libuuid-b4e7a346ee81bed0.rmeta --cap-lints=warn --crate-version 0.0.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "247e782c9b3e076bd7f0a00642ee4e5bd6a771899832810d2e2030ee05b63681", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "247e782c9b3e076bd7f0a00642ee4e5bd6a771899832810d2e2030ee05b63681", kill_on_drop: false }`
[INFO] [stdout] 247e782c9b3e076bd7f0a00642ee4e5bd6a771899832810d2e2030ee05b63681