[INFO] fetching crate msiz_rustc-ap-serialize 3.0.0...
[INFO] documenting msiz_rustc-ap-serialize-3.0.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate msiz_rustc-ap-serialize 3.0.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate msiz_rustc-ap-serialize 3.0.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate msiz_rustc-ap-serialize 3.0.0
[INFO] finished tweaking crates.io crate msiz_rustc-ap-serialize 3.0.0
[INFO] tweaked toml for crates.io crate msiz_rustc-ap-serialize 3.0.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9655efcab2553dd5906b142f81fb706675708af9f2456185bc1ae2cb8c867418
[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" "9655efcab2553dd5906b142f81fb706675708af9f2456185bc1ae2cb8c867418", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9655efcab2553dd5906b142f81fb706675708af9f2456185bc1ae2cb8c867418", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9655efcab2553dd5906b142f81fb706675708af9f2456185bc1ae2cb8c867418", kill_on_drop: false }`
[INFO] [stdout] 9655efcab2553dd5906b142f81fb706675708af9f2456185bc1ae2cb8c867418
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7dd2c271a6aaa2ceb0994808cf68930fac154bcceeaef9b72588d8f02b0d86f7
[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" "7dd2c271a6aaa2ceb0994808cf68930fac154bcceeaef9b72588d8f02b0d86f7", kill_on_drop: false }`
[INFO] [stderr]     Checking hashbrown v0.9.1
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]     Checking smallvec v0.6.13
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-0.6.13/lib.rs:32:32
[INFO] [stdout]    |
[INFO] [stdout] 32 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-0.6.13/lib.rs:34:37
[INFO] [stdout]    |
[INFO] [stdout] 34 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[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 compile `smallvec`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "7dd2c271a6aaa2ceb0994808cf68930fac154bcceeaef9b72588d8f02b0d86f7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7dd2c271a6aaa2ceb0994808cf68930fac154bcceeaef9b72588d8f02b0d86f7", kill_on_drop: false }`
[INFO] [stdout] 7dd2c271a6aaa2ceb0994808cf68930fac154bcceeaef9b72588d8f02b0d86f7
