[INFO] cloning repository https://github.com/jnicklas/rustos
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jnicklas/rustos" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjnicklas%2Frustos", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjnicklas%2Frustos'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c92baec15bbf9c737b6e52b843905d62aec50222
[INFO] documenting jnicklas/rustos against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjnicklas%2Frustos" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jnicklas/rustos 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 git repo https://github.com/jnicklas/rustos
[INFO] finished tweaking git repo https://github.com/jnicklas/rustos
[INFO] tweaked toml for git repo https://github.com/jnicklas/rustos written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/jnicklas/rustos 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] [stderr] error: the lock file /workspace/builds/worker-7/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] ea4cf76cacbb56e8bd11a8c7a3bbfc26b02d27c3c13b55b1ec3cb6b7c281835e
[INFO] running `Command { std: "docker" "start" "-a" "ea4cf76cacbb56e8bd11a8c7a3bbfc26b02d27c3c13b55b1ec3cb6b7c281835e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ea4cf76cacbb56e8bd11a8c7a3bbfc26b02d27c3c13b55b1ec3cb6b7c281835e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea4cf76cacbb56e8bd11a8c7a3bbfc26b02d27c3c13b55b1ec3cb6b7c281835e", kill_on_drop: false }`
[INFO] [stdout] ea4cf76cacbb56e8bd11a8c7a3bbfc26b02d27c3c13b55b1ec3cb6b7c281835e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] ea9b7acb305cebb311a4d42233dfff1c91cbb250b22028710771a9b1f130477b
[INFO] running `Command { std: "docker" "start" "-a" "ea9b7acb305cebb311a4d42233dfff1c91cbb250b22028710771a9b1f130477b", kill_on_drop: false }`
[INFO] [stderr]     Checking spin v0.5.2
[INFO] [stderr]     Checking rlibc v1.0.0
[INFO] [stderr]  Documenting rustos v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(no_std, lang_items, const_fn, unique, core_str_ext)]
[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 `rustos`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type staticlib --crate-name rustos 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 rlibc=/opt/rustwide/target/debug/deps/librlibc-b27f12e9d3d31c83.rmeta --extern spin=/opt/rustwide/target/debug/deps/libspin-44611bfc2a91f162.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "ea9b7acb305cebb311a4d42233dfff1c91cbb250b22028710771a9b1f130477b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea9b7acb305cebb311a4d42233dfff1c91cbb250b22028710771a9b1f130477b", kill_on_drop: false }`
[INFO] [stdout] ea9b7acb305cebb311a4d42233dfff1c91cbb250b22028710771a9b1f130477b