[INFO] fetching crate brioche 0.0.0...
[INFO] documenting brioche-0.0.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate brioche 0.0.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate brioche 0.0.0 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate brioche 0.0.0
[INFO] finished tweaking crates.io crate brioche 0.0.0
[INFO] tweaked toml for crates.io crate brioche 0.0.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate crates.io crate brioche 0.0.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d0d08fbd224496d81462b9791eee7535fb32d65929b1b2b136dfeb12803967a5
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "d0d08fbd224496d81462b9791eee7535fb32d65929b1b2b136dfeb12803967a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d0d08fbd224496d81462b9791eee7535fb32d65929b1b2b136dfeb12803967a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d0d08fbd224496d81462b9791eee7535fb32d65929b1b2b136dfeb12803967a5", kill_on_drop: false }`
[INFO] [stdout] d0d08fbd224496d81462b9791eee7535fb32d65929b1b2b136dfeb12803967a5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f628eeb1a45ec6739535fa0f78a9bdba0e47fae6927b2913a8f38314d54d3c4c
[INFO] running `Command { std: "docker" "start" "-a" "f628eeb1a45ec6739535fa0f78a9bdba0e47fae6927b2913a8f38314d54d3c4c", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.15
[INFO] [stderr]     Checking cesu8 v1.1.0
[INFO] [stderr]    Compiling brioche-ducc-sys v0.1.2-brioche
[INFO] [stderr]     Checking brioche-ducc v0.1.2-brioche
[INFO] [stderr]    Compiling syn-mid v0.5.0
[INFO] [stderr]    Compiling synstructure v0.12.3
[INFO] [stderr]    Compiling rustversion v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]    Compiling proc-macro-error v0.4.9
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.9
[INFO] [stderr]    Compiling err-derive v0.2.2
[INFO] [stderr]    Compiling structopt-derive v0.4.2
[INFO] [stderr]     Checking structopt v0.3.9
[INFO] [stderr]     Checking serde v1.0.104
[INFO] [stderr]     Checking brioche-ducc-serde v0.1.2-brioche
[INFO] [stderr]     Checking serde_json v1.0.48
[INFO] [stderr]  Documenting brioche v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(inner_deref)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `brioche`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name brioche src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern ducc=/opt/rustwide/target/debug/deps/libbrioche_ducc-e9c320ff758baf82.rmeta --extern ducc_serde=/opt/rustwide/target/debug/deps/libbrioche_ducc_serde-f1ec3091c0cf6671.rmeta --extern err_derive=/opt/rustwide/target/debug/deps/liberr_derive-9d325d09889fcd5a.so --extern serde=/opt/rustwide/target/debug/deps/libserde-892943948d111dcf.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-25e8bce33e78c35b.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-502571b8a56be938.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "f628eeb1a45ec6739535fa0f78a9bdba0e47fae6927b2913a8f38314d54d3c4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f628eeb1a45ec6739535fa0f78a9bdba0e47fae6927b2913a8f38314d54d3c4c", kill_on_drop: false }`
[INFO] [stdout] f628eeb1a45ec6739535fa0f78a9bdba0e47fae6927b2913a8f38314d54d3c4c