[INFO] cloning repository https://github.com/DanielKeep/calendar-example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/DanielKeep/calendar-example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDanielKeep%2Fcalendar-example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDanielKeep%2Fcalendar-example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 399f1b0fafac49df5e52a57b350a9c8b09ea046b
[INFO] documenting DanielKeep/calendar-example 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%2FDanielKeep%2Fcalendar-example" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/DanielKeep/calendar-example 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/DanielKeep/calendar-example
[INFO] finished tweaking git repo https://github.com/DanielKeep/calendar-example
[INFO] tweaked toml for git repo https://github.com/DanielKeep/calendar-example written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/DanielKeep/calendar-example 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 33c8beef745a696724acf0ab0991f45a5e0704d5e113e167e2e0bef4894b1bdd
[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" "33c8beef745a696724acf0ab0991f45a5e0704d5e113e167e2e0bef4894b1bdd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "33c8beef745a696724acf0ab0991f45a5e0704d5e113e167e2e0bef4894b1bdd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "33c8beef745a696724acf0ab0991f45a5e0704d5e113e167e2e0bef4894b1bdd", kill_on_drop: false }`
[INFO] [stdout] 33c8beef745a696724acf0ab0991f45a5e0704d5e113e167e2e0bef4894b1bdd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] fd85404f87178deacec2b283bc8c4d84f5b4f704abdc813b4bf5ad1b46e20137
[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" "fd85404f87178deacec2b283bc8c4d84f5b4f704abdc813b4bf5ad1b46e20137", kill_on_drop: false }`
[INFO] [stderr]     Checking num-traits v0.1.34
[INFO] [stderr]     Checking libc v0.2.15
[INFO] [stderr]     Checking itertools v0.4.17
[INFO] [stderr]     Checking time v0.1.35
[INFO] [stderr]     Checking num-integer v0.1.32
[INFO] [stderr]     Checking num-iter v0.1.32
[INFO] [stderr]     Checking num v0.1.34
[INFO] [stderr]     Checking chrono v0.2.25
[INFO] [stderr]  Documenting calendar v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> bin.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![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 `calendar`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name calendar bin.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern chrono=/opt/rustwide/target/debug/deps/libchrono-c1065b06ecd0f9c1.rmeta --extern itertools=/opt/rustwide/target/debug/deps/libitertools-96886ad2354e29b6.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "fd85404f87178deacec2b283bc8c4d84f5b4f704abdc813b4bf5ad1b46e20137", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fd85404f87178deacec2b283bc8c4d84f5b4f704abdc813b4bf5ad1b46e20137", kill_on_drop: false }`
[INFO] [stdout] fd85404f87178deacec2b283bc8c4d84f5b4f704abdc813b4bf5ad1b46e20137