[INFO] cloning repository https://github.com/mastfissh/rust-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mastfissh/rust-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmastfissh%2Frust-playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmastfissh%2Frust-playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a68ef69286ea46f25cc9243d5b54d356c7d49416
[INFO] documenting mastfissh/rust-playground 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%2Fmastfissh%2Frust-playground" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mastfissh/rust-playground 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/mastfissh/rust-playground
[INFO] finished tweaking git repo https://github.com/mastfissh/rust-playground
[INFO] tweaked toml for git repo https://github.com/mastfissh/rust-playground written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/mastfissh/rust-playground 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]     Blocking waiting for file lock on package cache
[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] 88d30aabe1b454cb5de3dcd7731fd527363f920702b114519cf7b1b870f9807a
[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" "88d30aabe1b454cb5de3dcd7731fd527363f920702b114519cf7b1b870f9807a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "88d30aabe1b454cb5de3dcd7731fd527363f920702b114519cf7b1b870f9807a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "88d30aabe1b454cb5de3dcd7731fd527363f920702b114519cf7b1b870f9807a", kill_on_drop: false }`
[INFO] [stdout] 88d30aabe1b454cb5de3dcd7731fd527363f920702b114519cf7b1b870f9807a
[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] 89592c15d591ad7f59fcf4521c5b80d433c9de7fc782ac1434173f2022ffd453
[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" "89592c15d591ad7f59fcf4521c5b80d433c9de7fc782ac1434173f2022ffd453", kill_on_drop: false }`
[INFO] [stderr]    Compiling ansi_term v0.9.0
[INFO] [stderr]    Compiling matches v0.1.4
[INFO] [stderr]    Compiling libc v0.2.22
[INFO] [stderr]    Compiling version_check v0.1.0
[INFO] [stderr]    Compiling unicode-normalization v0.1.4
[INFO] [stderr]    Compiling byteorder v1.0.0
[INFO] [stderr]    Compiling log v0.3.7
[INFO] [stderr]    Compiling httparse v1.2.2
[INFO] [stderr]    Compiling typeable v0.1.2
[INFO] [stderr]    Compiling language-tags v0.2.2
[INFO] [stderr]    Compiling term v0.4.5
[INFO] [stderr]    Compiling traitobject v0.1.0
[INFO] [stderr]    Compiling state v0.2.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/state-0.2.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `state`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/state-0.2.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "89592c15d591ad7f59fcf4521c5b80d433c9de7fc782ac1434173f2022ffd453", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "89592c15d591ad7f59fcf4521c5b80d433c9de7fc782ac1434173f2022ffd453", kill_on_drop: false }`
[INFO] [stdout] 89592c15d591ad7f59fcf4521c5b80d433c9de7fc782ac1434173f2022ffd453