[INFO] fetching crate ipc 0.2.0...
[INFO] documenting ipc-0.2.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate ipc 0.2.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate ipc 0.2.0 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ipc 0.2.0
[INFO] finished tweaking crates.io crate ipc 0.2.0
[INFO] tweaked toml for crates.io crate ipc 0.2.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b8f52eb1a4e6ea89cd7e903f9e02c9ec1af2e5711086af7d5d3086dce0abe009
[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" "b8f52eb1a4e6ea89cd7e903f9e02c9ec1af2e5711086af7d5d3086dce0abe009", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b8f52eb1a4e6ea89cd7e903f9e02c9ec1af2e5711086af7d5d3086dce0abe009", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8f52eb1a4e6ea89cd7e903f9e02c9ec1af2e5711086af7d5d3086dce0abe009", kill_on_drop: false }`
[INFO] [stdout] b8f52eb1a4e6ea89cd7e903f9e02c9ec1af2e5711086af7d5d3086dce0abe009
[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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 17a3d5aa8eb441cb13a569c741b4294d189dfda671e379f8b188bc6a7594c3c1
[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" "17a3d5aa8eb441cb13a569c741b4294d189dfda671e379f8b188bc6a7594c3c1", kill_on_drop: false }`
[INFO] [stderr]  Documenting ipc v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro, conservative_impl_trait, generators)]
[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`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name ipc 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 futures=/opt/rustwide/target/debug/deps/libfutures-f6a782863e1804d0.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-b01e5f49cd1b74e8.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-8b25aaf2e71705fc.rmeta --extern rmp_serde=/opt/rustwide/target/debug/deps/librmp_serde-82998ecd834642f8.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-ec5e695d7e4b5284.rmeta --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-e14ca5de376ec3cc.so --extern tokio_io=/opt/rustwide/target/debug/deps/libtokio_io-a71d4c184e635d22.rmeta --cap-lints=warn --crate-version 0.2.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "17a3d5aa8eb441cb13a569c741b4294d189dfda671e379f8b188bc6a7594c3c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "17a3d5aa8eb441cb13a569c741b4294d189dfda671e379f8b188bc6a7594c3c1", kill_on_drop: false }`
[INFO] [stdout] 17a3d5aa8eb441cb13a569c741b4294d189dfda671e379f8b188bc6a7594c3c1