[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 1.54.0 for beta-1.55-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnooberfsh%2Fheartbeat" "/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/nooberfsh/heartbeat on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-4/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" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0e99f0efea70ee17ae2a6cf9f8f1abbd3eb449da487592bab30926526ea9950c
[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" "0e99f0efea70ee17ae2a6cf9f8f1abbd3eb449da487592bab30926526ea9950c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0e99f0efea70ee17ae2a6cf9f8f1abbd3eb449da487592bab30926526ea9950c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0e99f0efea70ee17ae2a6cf9f8f1abbd3eb449da487592bab30926526ea9950c", kill_on_drop: false }`
[INFO] [stdout] 0e99f0efea70ee17ae2a6cf9f8f1abbd3eb449da487592bab30926526ea9950c
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a25b97941b84273e6d27f87bce73fb2a90721390401ba3ce5532b8ad3598fbd4
[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" "a25b97941b84273e6d27f87bce73fb2a90721390401ba3ce5532b8ad3598fbd4", kill_on_drop: false }`
[INFO] [stderr]     Checking lazycell v0.5.1
[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]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `conservative_impl_trait` has been stable since 1.26.0 and no longer requires an attribute to enable
[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-c2735e06d165e1a5.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-24e5bf786a40a441.rmeta --extern tokio_core=/opt/rustwide/target/debug/deps/libtokio_core-d8c03a62ce9e1a08.rmeta --extern tokio_io=/opt/rustwide/target/debug/deps/libtokio_io-db4e90cf7bfb58a2.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "a25b97941b84273e6d27f87bce73fb2a90721390401ba3ce5532b8ad3598fbd4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a25b97941b84273e6d27f87bce73fb2a90721390401ba3ce5532b8ad3598fbd4", kill_on_drop: false }`
[INFO] [stdout] a25b97941b84273e6d27f87bce73fb2a90721390401ba3ce5532b8ad3598fbd4
