[INFO] fetching crate ipc-rs 0.4.2...
[INFO] documenting ipc-rs-0.4.2 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate ipc-rs 0.4.2 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate ipc-rs 0.4.2 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 ipc-rs 0.4.2
[INFO] finished tweaking crates.io crate ipc-rs 0.4.2
[INFO] tweaked toml for crates.io crate ipc-rs 0.4.2 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] a687a112e476424f6bf486f0e862c108d0d65c38591e326ab3f7486deff79b40
[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" "a687a112e476424f6bf486f0e862c108d0d65c38591e326ab3f7486deff79b40", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a687a112e476424f6bf486f0e862c108d0d65c38591e326ab3f7486deff79b40", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a687a112e476424f6bf486f0e862c108d0d65c38591e326ab3f7486deff79b40", kill_on_drop: false }`
[INFO] [stdout] a687a112e476424f6bf486f0e862c108d0d65c38591e326ab3f7486deff79b40
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stdout] c6b7f2a6c4889864549aa92493afcef2bdae7053a0cfe68cf397b9be6b343ab2
[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" "c6b7f2a6c4889864549aa92493afcef2bdae7053a0cfe68cf397b9be6b343ab2", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling nix v0.11.1
[INFO] [stderr]     Checking half v1.6.0
[INFO] [stderr]     Checking serde_cbor v0.9.0
[INFO] [stderr]  Documenting ipc-rs v0.4.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:10:1
[INFO] [stdout]    |
[INFO] [stdout] 10 | #![feature(associated_type_defaults)]
[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 `ipc-rs`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name ipc_rs src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern libc=/opt/rustwide/target/debug/deps/liblibc-1ad3ad1e20beb97f.rmeta --extern nix=/opt/rustwide/target/debug/deps/libnix-fd0758429a6d2482.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-5429dd6d097468fb.rmeta --extern serde_cbor=/opt/rustwide/target/debug/deps/libserde_cbor-0f8df1fe3117d488.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "c6b7f2a6c4889864549aa92493afcef2bdae7053a0cfe68cf397b9be6b343ab2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c6b7f2a6c4889864549aa92493afcef2bdae7053a0cfe68cf397b9be6b343ab2", kill_on_drop: false }`
[INFO] [stdout] c6b7f2a6c4889864549aa92493afcef2bdae7053a0cfe68cf397b9be6b343ab2