[INFO] fetching crate pgc 0.3.0...
[INFO] documenting pgc-0.3.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate pgc 0.3.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate pgc 0.3.0 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 pgc 0.3.0
[INFO] finished tweaking crates.io crate pgc 0.3.0
[INFO] tweaked toml for crates.io crate pgc 0.3.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate pgc 0.3.0 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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 2a96f3f5393f7ea48a52d85c4ea33fe08d5e736a625541400545f7db1a6e2297
[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" "2a96f3f5393f7ea48a52d85c4ea33fe08d5e736a625541400545f7db1a6e2297", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2a96f3f5393f7ea48a52d85c4ea33fe08d5e736a625541400545f7db1a6e2297", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a96f3f5393f7ea48a52d85c4ea33fe08d5e736a625541400545f7db1a6e2297", kill_on_drop: false }`
[INFO] [stdout] 2a96f3f5393f7ea48a52d85c4ea33fe08d5e736a625541400545f7db1a6e2297
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 7112970ce8f8b7ccfe90d3a8266338d3e514a56ebcb8ac5bf87b4599b48dc177
[INFO] running `Command { std: "docker" "start" "-a" "7112970ce8f8b7ccfe90d3a8266338d3e514a56ebcb8ac5bf87b4599b48dc177", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling cmake v0.1.42
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking threadpool v1.7.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling libmimalloc-sys v0.1.6
[INFO] [stderr]     Checking mimalloc v0.1.9
[INFO] [stderr]  Documenting pgc v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(coerce_unsized)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(unsize)]
[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 `pgc`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name pgc src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern crossbeam_deque=/opt/rustwide/target/debug/deps/libcrossbeam_deque-09c65de2b85ebf5a.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-57a7edc7f441d44c.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-13bf4e33c96eb643.rmeta --extern mimalloc=/opt/rustwide/target/debug/deps/libmimalloc-e989c20671cc543f.rmeta --extern num_cpus=/opt/rustwide/target/debug/deps/libnum_cpus-d3f6c4d49ddf507d.rmeta --extern parking_lot=/opt/rustwide/target/debug/deps/libparking_lot-a267257e3659a409.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-6f1e36bf3a9023ce.rmeta --extern scoped_threadpool=/opt/rustwide/target/debug/deps/libscoped_threadpool-64fb84bc1deb38e7.rmeta --extern threadpool=/opt/rustwide/target/debug/deps/libthreadpool-39fecd9e70a08845.rmeta --extern time=/opt/rustwide/target/debug/deps/libtime-d864f51faf8cc277.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "7112970ce8f8b7ccfe90d3a8266338d3e514a56ebcb8ac5bf87b4599b48dc177", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7112970ce8f8b7ccfe90d3a8266338d3e514a56ebcb8ac5bf87b4599b48dc177", kill_on_drop: false }`
[INFO] [stdout] 7112970ce8f8b7ccfe90d3a8266338d3e514a56ebcb8ac5bf87b4599b48dc177