[INFO] fetching crate smt2 0.1.0...
[INFO] documenting smt2-0.1.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate smt2 0.1.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate smt2 0.1.0 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate smt2 0.1.0
[INFO] finished tweaking crates.io crate smt2 0.1.0
[INFO] tweaked toml for crates.io crate smt2 0.1.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded utf8-decode v1.0.1
[INFO] [stderr]   Downloaded source-span v1.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 39f9171f1650f69c169adb253d255bc93b282d6310b6b86fc3b0b15079d73943
[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" "39f9171f1650f69c169adb253d255bc93b282d6310b6b86fc3b0b15079d73943", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "39f9171f1650f69c169adb253d255bc93b282d6310b6b86fc3b0b15079d73943", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39f9171f1650f69c169adb253d255bc93b282d6310b6b86fc3b0b15079d73943", kill_on_drop: false }`
[INFO] [stdout] 39f9171f1650f69c169adb253d255bc93b282d6310b6b86fc3b0b15079d73943
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a29915a814539d55e6dc8589700a2b4b40047335b490959edcb97650d006d0f9
[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" "a29915a814539d55e6dc8589700a2b4b40047335b490959edcb97650d006d0f9", kill_on_drop: false }`
[INFO] [stderr]     Checking utf8-decode v1.0.1
[INFO] [stderr]     Checking source-span v1.4.0
[INFO] [stderr]  Documenting smt2 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta 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 --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern source_span=/opt/rustwide/target/debug/deps/libsource_span-10f90b4f9fb2006c.rmeta --extern utf8_decode=/opt/rustwide/target/debug/deps/libutf8_decode-5126368c59fe123c.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "a29915a814539d55e6dc8589700a2b4b40047335b490959edcb97650d006d0f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a29915a814539d55e6dc8589700a2b4b40047335b490959edcb97650d006d0f9", kill_on_drop: false }`
[INFO] [stdout] a29915a814539d55e6dc8589700a2b4b40047335b490959edcb97650d006d0f9