[INFO] cloning repository https://github.com/fin-ger/declarative-state-machine
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fin-ger/declarative-state-machine" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffin-ger%2Fdeclarative-state-machine", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffin-ger%2Fdeclarative-state-machine'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 301f8d92408bed8eb92b99caf23175da73673c6a
[INFO] documenting fin-ger/declarative-state-machine 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%2Ffin-ger%2Fdeclarative-state-machine" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fin-ger/declarative-state-machine 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/fin-ger/declarative-state-machine
[INFO] finished tweaking git repo https://github.com/fin-ger/declarative-state-machine
[INFO] tweaked toml for git repo https://github.com/fin-ger/declarative-state-machine written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/fin-ger/declarative-state-machine 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-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] 368bd32ac16106be292c4abeaa29220af39e9337cae84c1cb3f74b5f6b29ff0f
[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" "368bd32ac16106be292c4abeaa29220af39e9337cae84c1cb3f74b5f6b29ff0f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "368bd32ac16106be292c4abeaa29220af39e9337cae84c1cb3f74b5f6b29ff0f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "368bd32ac16106be292c4abeaa29220af39e9337cae84c1cb3f74b5f6b29ff0f", kill_on_drop: false }`
[INFO] [stdout] 368bd32ac16106be292c4abeaa29220af39e9337cae84c1cb3f74b5f6b29ff0f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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] 4555357a654f6fddffd5ef7ceb1e1190d12d04f2d3b36f70151e29f33981adc1
[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" "4555357a654f6fddffd5ef7ceb1e1190d12d04f2d3b36f70151e29f33981adc1", kill_on_drop: false }`
[INFO] [stderr]     Checking proc-macro2 v0.4.27
[INFO] [stderr]    Compiling syn v0.15.27
[INFO] [stderr]     Checking quote v0.6.11
[INFO] [stderr]  Documenting declarative-state-machine v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(proc_macro_diagnostic)]
[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 `declarative-state-machine`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type proc-macro --crate-name declarative_state_machine src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-03d20cb13f1e62ed.rmeta --extern quick_error=/opt/rustwide/target/debug/deps/libquick_error-33ea2cc8d53e5b67.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-0ac786822b9617e7.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-b41ea738611a1789.rmeta --extern proc_macro --cap-lints=warn` (exit code: 1)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "4555357a654f6fddffd5ef7ceb1e1190d12d04f2d3b36f70151e29f33981adc1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4555357a654f6fddffd5ef7ceb1e1190d12d04f2d3b36f70151e29f33981adc1", kill_on_drop: false }`
[INFO] [stdout] 4555357a654f6fddffd5ef7ceb1e1190d12d04f2d3b36f70151e29f33981adc1