[INFO] cloning repository https://github.com/fun4wut/naive-concurrent
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fun4wut/naive-concurrent" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffun4wut%2Fnaive-concurrent", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffun4wut%2Fnaive-concurrent'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f05a13d9e9e20947d08b65a6adcc6d21b327c850
[INFO] documenting fun4wut/naive-concurrent 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%2Ffun4wut%2Fnaive-concurrent" "/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/fun4wut/naive-concurrent 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/fun4wut/naive-concurrent
[INFO] finished tweaking git repo https://github.com/fun4wut/naive-concurrent
[INFO] tweaked toml for git repo https://github.com/fun4wut/naive-concurrent written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/fun4wut/naive-concurrent 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-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] [stdout] b9b0db685e74c36c548df8ed9e8373213e627a65dfebfd54a3978e066cc0fa01
[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" "b9b0db685e74c36c548df8ed9e8373213e627a65dfebfd54a3978e066cc0fa01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b9b0db685e74c36c548df8ed9e8373213e627a65dfebfd54a3978e066cc0fa01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b9b0db685e74c36c548df8ed9e8373213e627a65dfebfd54a3978e066cc0fa01", kill_on_drop: false }`
[INFO] [stdout] b9b0db685e74c36c548df8ed9e8373213e627a65dfebfd54a3978e066cc0fa01
[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] [stdout] d05668e8d0a1663a0ea9ca94ae312e86d753dc9246b85150b2fa816c61e9ffa8
[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" "d05668e8d0a1663a0ea9ca94ae312e86d753dc9246b85150b2fa816c61e9ffa8", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]     Checking async-task v1.0.0
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking async-macros v1.0.0
[INFO] [stderr]     Checking kv-log-macro v1.0.4
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]     Checking crossbeam v0.7.2
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking scheduled-thread-pool v0.2.2
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]     Checking futures-timer v1.0.2
[INFO] [stderr]     Checking broadcaster v0.2.6
[INFO] [stderr]     Checking async-std v0.99.10
[INFO] [stderr]  Documenting webserver 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(box_syntax)]
[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 `webserver`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name webserver 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 async_std=/opt/rustwide/target/debug/deps/libasync_std-b8a1c7023f2da10b.rmeta --extern crossbeam=/opt/rustwide/target/debug/deps/libcrossbeam-df2264ac427e85dd.rmeta --extern futures_timer=/opt/rustwide/target/debug/deps/libfutures_timer-606922de970d9505.rmeta --extern scheduled_thread_pool=/opt/rustwide/target/debug/deps/libscheduled_thread_pool-bbe3ca7008280976.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "d05668e8d0a1663a0ea9ca94ae312e86d753dc9246b85150b2fa816c61e9ffa8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d05668e8d0a1663a0ea9ca94ae312e86d753dc9246b85150b2fa816c61e9ffa8", kill_on_drop: false }`
[INFO] [stdout] d05668e8d0a1663a0ea9ca94ae312e86d753dc9246b85150b2fa816c61e9ffa8