[INFO] fetching crate smt2 0.2.0...
[INFO] documenting smt2-0.2.0 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate smt2 0.2.0 into /workspace/builds/worker-19/source
[INFO] validating manifest of crates.io crate smt2 0.2.0 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate smt2 0.2.0
[INFO] finished tweaking crates.io crate smt2 0.2.0
[INFO] tweaked toml for crates.io crate smt2 0.2.0 written to /workspace/builds/worker-19/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "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" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded source-span v2.7.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 51fa68218c65495f492cb650b71d78a35ae6776454e3008da6d5a48250d2d965
[INFO] running `Command { std: "docker" "start" "-a" "51fa68218c65495f492cb650b71d78a35ae6776454e3008da6d5a48250d2d965", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "51fa68218c65495f492cb650b71d78a35ae6776454e3008da6d5a48250d2d965", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51fa68218c65495f492cb650b71d78a35ae6776454e3008da6d5a48250d2d965", kill_on_drop: false }`
[INFO] [stdout] 51fa68218c65495f492cb650b71d78a35ae6776454e3008da6d5a48250d2d965
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d8f5cb781c4235d285ccd5e21a2f7686b9155a97f7f112345a11e009e0871131
[INFO] running `Command { std: "docker" "start" "-a" "d8f5cb781c4235d285ccd5e21a2f7686b9155a97f7f112345a11e009e0871131", kill_on_drop: false }`
[INFO] [stderr]     Checking numtoa v0.1.0
[INFO] [stderr]     Checking utf8-decode v1.0.1
[INFO] [stderr]     Checking termion v1.5.6
[INFO] [stderr]     Checking source-span v2.7.0
[INFO] [stderr]  Documenting smt2 v0.2.0 (/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(trait_alias)]
[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 `smt2`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name smt2 src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=36d95a48a71ead35 -L dependency=/opt/rustwide/target/debug/deps --extern source_span=/opt/rustwide/target/debug/deps/libsource_span-75bfae61f432dd46.rmeta --extern utf8_decode=/opt/rustwide/target/debug/deps/libutf8_decode-3cdc113e177c0572.rmeta --cap-lints=warn --crate-version 0.2.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "d8f5cb781c4235d285ccd5e21a2f7686b9155a97f7f112345a11e009e0871131", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d8f5cb781c4235d285ccd5e21a2f7686b9155a97f7f112345a11e009e0871131", kill_on_drop: false }`
[INFO] [stdout] d8f5cb781c4235d285ccd5e21a2f7686b9155a97f7f112345a11e009e0871131