[INFO] cloning repository https://github.com/luciusmagn/ipc-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/luciusmagn/ipc-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluciusmagn%2Fipc-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluciusmagn%2Fipc-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e6179c538f1e1d7bbcdc17f745757fede29c4dc8
[INFO] documenting luciusmagn/ipc-rs against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluciusmagn%2Fipc-rs" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/luciusmagn/ipc-rs 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 git repo https://github.com/luciusmagn/ipc-rs
[INFO] finished tweaking git repo https://github.com/luciusmagn/ipc-rs
[INFO] tweaked toml for git repo https://github.com/luciusmagn/ipc-rs written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/luciusmagn/ipc-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded nix v0.11.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 8266998d2e17120c1997b10cd728bf8bda0ffd728f860b21fcbf9aaa1b650edf
[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" "8266998d2e17120c1997b10cd728bf8bda0ffd728f860b21fcbf9aaa1b650edf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8266998d2e17120c1997b10cd728bf8bda0ffd728f860b21fcbf9aaa1b650edf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8266998d2e17120c1997b10cd728bf8bda0ffd728f860b21fcbf9aaa1b650edf", kill_on_drop: false }`
[INFO] [stdout] 8266998d2e17120c1997b10cd728bf8bda0ffd728f860b21fcbf9aaa1b650edf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] d33cd4f565993e3a67e9364e138e8bd590c25db0c898a48b0e4e8f258e95f964
[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" "d33cd4f565993e3a67e9364e138e8bd590c25db0c898a48b0e4e8f258e95f964", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling serde v1.0.94
[INFO] [stderr]    Compiling nix v0.11.1
[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 beta 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-1a598bca542e9597.rmeta --extern nix=/opt/rustwide/target/debug/deps/libnix-15b1f02ba72ab0ed.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-a4fd965b04670460.rmeta --extern serde_cbor=/opt/rustwide/target/debug/deps/libserde_cbor-299877bd1ac0159e.rmeta --cap-lints=warn --crate-version 0.4.2` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "d33cd4f565993e3a67e9364e138e8bd590c25db0c898a48b0e4e8f258e95f964", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d33cd4f565993e3a67e9364e138e8bd590c25db0c898a48b0e4e8f258e95f964", kill_on_drop: false }`
[INFO] [stdout] d33cd4f565993e3a67e9364e138e8bd590c25db0c898a48b0e4e8f258e95f964