[INFO] cloning repository https://github.com/nooberfsh/heartbeat
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nooberfsh/heartbeat" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnooberfsh%2Fheartbeat", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnooberfsh%2Fheartbeat'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9686d1313fe68c709f5016741308075d0da2c605
[INFO] documenting nooberfsh/heartbeat 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%2Fnooberfsh%2Fheartbeat" "/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/nooberfsh/heartbeat 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/nooberfsh/heartbeat
[INFO] finished tweaking git repo https://github.com/nooberfsh/heartbeat
[INFO] tweaked toml for git repo https://github.com/nooberfsh/heartbeat written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/nooberfsh/heartbeat 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] 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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4438b85eaabb7c52b33e0233fb75b9c0d923a299ed916b163f66e3fe3f4c71ec
[INFO] running `Command { std: "docker" "start" "-a" "4438b85eaabb7c52b33e0233fb75b9c0d923a299ed916b163f66e3fe3f4c71ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4438b85eaabb7c52b33e0233fb75b9c0d923a299ed916b163f66e3fe3f4c71ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4438b85eaabb7c52b33e0233fb75b9c0d923a299ed916b163f66e3fe3f4c71ec", kill_on_drop: false }`
[INFO] [stdout] 4438b85eaabb7c52b33e0233fb75b9c0d923a299ed916b163f66e3fe3f4c71ec
[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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a2508eff8bebf001883b52dd40d0b5f74fb1ed23a15615e1cde47533d90db368
[INFO] running `Command { std: "docker" "start" "-a" "a2508eff8bebf001883b52dd40d0b5f74fb1ed23a15615e1cde47533d90db368", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.2
[INFO] [stderr]     Checking lazycell v0.5.1
[INFO] [stderr]     Checking scoped-tls v0.1.0
[INFO] [stderr]     Checking iovec v0.1.1
[INFO] [stderr]     Checking net2 v0.2.31
[INFO] [stderr]     Checking bytes v0.4.5
[INFO] [stderr]     Checking mio v0.6.11
[INFO] [stderr]     Checking tokio-io v0.1.3
[INFO] [stderr]     Checking tokio-core v0.1.10
[INFO] [stderr]  Documenting test-tokio v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(conservative_impl_trait)]
[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 `test-tokio`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name test_tokio src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern bytes=/opt/rustwide/target/debug/deps/libbytes-75635dfad56ca561.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-55154188e7f80348.rmeta --extern tokio_core=/opt/rustwide/target/debug/deps/libtokio_core-8b77472b0cb6d307.rmeta --extern tokio_io=/opt/rustwide/target/debug/deps/libtokio_io-a999b22666433e28.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "a2508eff8bebf001883b52dd40d0b5f74fb1ed23a15615e1cde47533d90db368", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a2508eff8bebf001883b52dd40d0b5f74fb1ed23a15615e1cde47533d90db368", kill_on_drop: false }`
[INFO] [stdout] a2508eff8bebf001883b52dd40d0b5f74fb1ed23a15615e1cde47533d90db368