[INFO] fetching crate boomerang_derive 0.1.0...
[INFO] documenting boomerang_derive-0.1.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate boomerang_derive 0.1.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate boomerang_derive 0.1.0 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 crates.io crate boomerang_derive 0.1.0
[INFO] finished tweaking crates.io crate boomerang_derive 0.1.0
[INFO] tweaked toml for crates.io crate boomerang_derive 0.1.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 83a4dcd067d3f68154bb979c55a5082f79a863b16020d2e8a591b5b386206c98
[INFO] running `Command { std: "docker" "start" "-a" "83a4dcd067d3f68154bb979c55a5082f79a863b16020d2e8a591b5b386206c98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "83a4dcd067d3f68154bb979c55a5082f79a863b16020d2e8a591b5b386206c98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "83a4dcd067d3f68154bb979c55a5082f79a863b16020d2e8a591b5b386206c98", kill_on_drop: false }`
[INFO] [stdout] 83a4dcd067d3f68154bb979c55a5082f79a863b16020d2e8a591b5b386206c98
[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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] c6021ac5bd820fb996bd62072c8022f50cac139f093331afa8354181ea31dfd0
[INFO] running `Command { std: "docker" "start" "-a" "c6021ac5bd820fb996bd62072c8022f50cac139f093331afa8354181ea31dfd0", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]     Checking unicode-xid v0.2.1
[INFO] [stderr]    Compiling strsim v0.9.3
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]     Checking fixedbitset v0.2.0
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling hashbrown v0.8.2
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling indexmap v1.5.2
[INFO] [stderr]     Checking proc-macro2 v1.0.19
[INFO] [stderr]     Checking quote v1.0.7
[INFO] [stderr]     Checking num-integer v0.1.43
[INFO] [stderr]     Checking petgraph v0.5.1
[INFO] [stderr]     Checking num-bigint v0.2.6
[INFO] [stderr]     Checking num v0.2.1
[INFO] [stderr]     Checking parse_duration v2.1.0
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling derive_more v0.99.9
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]     Checking darling v0.10.2
[INFO] [stderr]  Documenting boomerang_derive 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:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(hash_set_entry)]
[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 `boomerang_derive`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type proc-macro --crate-name boomerang_derive 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 darling=/opt/rustwide/target/debug/deps/libdarling-11e82bcab32ade0a.rmeta --extern derive_more=/opt/rustwide/target/debug/deps/libderive_more-0101019eb2ce45f7.so --extern parse_duration=/opt/rustwide/target/debug/deps/libparse_duration-f73603574bf04f31.rmeta --extern petgraph=/opt/rustwide/target/debug/deps/libpetgraph-5402046023d2dfe2.rmeta --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-17be1714580826fd.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-aa48b02cc1582459.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-a20c812ad2fc14a5.rmeta --extern proc_macro --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "c6021ac5bd820fb996bd62072c8022f50cac139f093331afa8354181ea31dfd0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c6021ac5bd820fb996bd62072c8022f50cac139f093331afa8354181ea31dfd0", kill_on_drop: false }`
[INFO] [stdout] c6021ac5bd820fb996bd62072c8022f50cac139f093331afa8354181ea31dfd0