[INFO] cloning repository https://github.com/Bietola/rwh-ch10-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Bietola/rwh-ch10-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBietola%2Frwh-ch10-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBietola%2Frwh-ch10-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0618c38f07cbfa3db2096707c9d31069408df054
[INFO] documenting Bietola/rwh-ch10-rust 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%2FBietola%2Frwh-ch10-rust" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Bietola/rwh-ch10-rust 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/Bietola/rwh-ch10-rust
[INFO] finished tweaking git repo https://github.com/Bietola/rwh-ch10-rust
[INFO] tweaked toml for git repo https://github.com/Bietola/rwh-ch10-rust written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/Bietola/rwh-ch10-rust 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-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] 0c787aa9da97a9473917f23102268a62af363a14d0c38768d2d910c5737a81b0
[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" "0c787aa9da97a9473917f23102268a62af363a14d0c38768d2d910c5737a81b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0c787aa9da97a9473917f23102268a62af363a14d0c38768d2d910c5737a81b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0c787aa9da97a9473917f23102268a62af363a14d0c38768d2d910c5737a81b0", kill_on_drop: false }`
[INFO] [stdout] 0c787aa9da97a9473917f23102268a62af363a14d0c38768d2d910c5737a81b0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] 7f59a008c86074f3c3ff17fee5161dfcb81181359ce64ff4d97f11cb5789563b
[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" "7f59a008c86074f3c3ff17fee5161dfcb81181359ce64ff4d97f11cb5789563b", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.35
[INFO] [stderr]    Compiling derive-newtype v0.2.3
[INFO] [stderr]     Checking bstr v0.2.13
[INFO] [stderr]     Checking newtype v0.2.1
[INFO] [stderr]    Compiling indoc-impl v0.3.6
[INFO] [stderr]     Checking indoc v0.3.6
[INFO] [stderr]  Documenting rwh-ch10-rust 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(result_flattening)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(trace_macros)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 `rwh-ch10-rust`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name rwh_ch10_rust 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 bstr=/opt/rustwide/target/debug/deps/libbstr-6933fee118855cc8.rmeta --extern indoc=/opt/rustwide/target/debug/deps/libindoc-cf57294ff441e8f4.rmeta --extern newtype=/opt/rustwide/target/debug/deps/libnewtype-70c2a45e8fdea1e4.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "7f59a008c86074f3c3ff17fee5161dfcb81181359ce64ff4d97f11cb5789563b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7f59a008c86074f3c3ff17fee5161dfcb81181359ce64ff4d97f11cb5789563b", kill_on_drop: false }`
[INFO] [stdout] 7f59a008c86074f3c3ff17fee5161dfcb81181359ce64ff4d97f11cb5789563b