[INFO] cloning repository https://github.com/juanibiapina/king
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/juanibiapina/king" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjuanibiapina%2Fking", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjuanibiapina%2Fking'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1c5a00fcd5ea423eba6579a8a7d7146f9b7e0d55
[INFO] documenting juanibiapina/king 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%2Fjuanibiapina%2Fking" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/juanibiapina/king 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/juanibiapina/king
[INFO] finished tweaking git repo https://github.com/juanibiapina/king
[INFO] tweaked toml for git repo https://github.com/juanibiapina/king written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/juanibiapina/king 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 ncurses v5.87.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7aaca7b646cab08f24842a1aeb21dbe26d79edce799f6031963439b4365fb732
[INFO] running `Command { std: "docker" "start" "-a" "7aaca7b646cab08f24842a1aeb21dbe26d79edce799f6031963439b4365fb732", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7aaca7b646cab08f24842a1aeb21dbe26d79edce799f6031963439b4365fb732", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7aaca7b646cab08f24842a1aeb21dbe26d79edce799f6031963439b4365fb732", kill_on_drop: false }`
[INFO] [stdout] 7aaca7b646cab08f24842a1aeb21dbe26d79edce799f6031963439b4365fb732
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 1fa9515802025786c7e0c1f5523fb27aae72cc082ccd640aa28fae235f52fb95
[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" "1fa9515802025786c7e0c1f5523fb27aae72cc082ccd640aa28fae235f52fb95", kill_on_drop: false }`
[INFO] [stderr]    Compiling ncurses v5.87.0
[INFO] [stderr]  Documenting king v0.1.0 (/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(splice)]
[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 `king`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name king 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-a2476888656e7afc.rmeta --extern ncurses=/opt/rustwide/target/debug/deps/libncurses-b1f646eaf44ac494.rmeta --extern unicode_segmentation=/opt/rustwide/target/debug/deps/libunicode_segmentation-160808f9d0667679.rmeta --extern unicode_width=/opt/rustwide/target/debug/deps/libunicode_width-e8cb5a16ea0467b1.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "1fa9515802025786c7e0c1f5523fb27aae72cc082ccd640aa28fae235f52fb95", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1fa9515802025786c7e0c1f5523fb27aae72cc082ccd640aa28fae235f52fb95", kill_on_drop: false }`
[INFO] [stdout] 1fa9515802025786c7e0c1f5523fb27aae72cc082ccd640aa28fae235f52fb95