[INFO] fetching crate msiz_rustc-ap-serialize 3.0.0...
[INFO] documenting msiz_rustc-ap-serialize-3.0.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate msiz_rustc-ap-serialize 3.0.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate msiz_rustc-ap-serialize 3.0.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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" "+1.54.0" "fetch" "--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-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 160e5493926763261ac03bee5c2d252e1f2a5ce055ba588660e38c243e8fdcdc
[INFO] running `Command { std: "docker" "start" "-a" "160e5493926763261ac03bee5c2d252e1f2a5ce055ba588660e38c243e8fdcdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "160e5493926763261ac03bee5c2d252e1f2a5ce055ba588660e38c243e8fdcdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "160e5493926763261ac03bee5c2d252e1f2a5ce055ba588660e38c243e8fdcdc", kill_on_drop: false }`
[INFO] [stdout] 160e5493926763261ac03bee5c2d252e1f2a5ce055ba588660e38c243e8fdcdc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 706cd7d5d5c8c83793c352f2c67e3a8bb6d1f23a9705787b67de262eff84f0e0
[INFO] running `Command { std: "docker" "start" "-a" "706cd7d5d5c8c83793c352f2c67e3a8bb6d1f23a9705787b67de262eff84f0e0", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking hashbrown v0.11.2
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]     Checking smallvec v0.6.14
[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-0.6.14/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-0.6.14/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" "706cd7d5d5c8c83793c352f2c67e3a8bb6d1f23a9705787b67de262eff84f0e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "706cd7d5d5c8c83793c352f2c67e3a8bb6d1f23a9705787b67de262eff84f0e0", kill_on_drop: false }`
[INFO] [stdout] 706cd7d5d5c8c83793c352f2c67e3a8bb6d1f23a9705787b67de262eff84f0e0
