[INFO] fetching crate lain 0.5.2...
[INFO] documenting lain-0.5.2 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate lain 0.5.2 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate lain 0.5.2 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 lain 0.5.2
[INFO] finished tweaking crates.io crate lain 0.5.2
[INFO] tweaked toml for crates.io crate lain 0.5.2 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 lain_derive v0.5.2
[INFO] [stderr]   Downloaded field-offset v0.3.2
[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] 5eabc953d9191f94c53a3b1a59ad16e052fe4c516aae1efe1153a6a5dbade552
[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" "5eabc953d9191f94c53a3b1a59ad16e052fe4c516aae1efe1153a6a5dbade552", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5eabc953d9191f94c53a3b1a59ad16e052fe4c516aae1efe1153a6a5dbade552", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5eabc953d9191f94c53a3b1a59ad16e052fe4c516aae1efe1153a6a5dbade552", kill_on_drop: false }`
[INFO] [stdout] 5eabc953d9191f94c53a3b1a59ad16e052fe4c516aae1efe1153a6a5dbade552
[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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 748477b478166af7a250ea73ca4f01a075e7097f18f46d1a68d443e94da0825f
[INFO] running `Command { std: "docker" "start" "-a" "748477b478166af7a250ea73ca4f01a075e7097f18f46d1a68d443e94da0825f", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro-hack-impl v0.4.2
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]    Compiling field-offset v0.3.2
[INFO] [stderr]    Compiling num-derive v0.2.5
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand_pcg v0.2.1
[INFO] [stderr]    Compiling proc-macro-hack v0.4.2
[INFO] [stderr]    Compiling mashup-impl v0.1.12
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]    Compiling mashup v0.1.12
[INFO] [stderr]    Compiling lain_derive v0.5.2
[INFO] [stderr]     Checking num v0.2.1
[INFO] [stderr]  Documenting lain v0.5.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]    --> src/lib.rs:101:1
[INFO] [stdout]     |
[INFO] [stdout] 101 | #![feature(specialization)]
[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 `lain`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name lain 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 byteorder=/opt/rustwide/target/debug/deps/libbyteorder-364c148656283980.rmeta --extern field_offset=/opt/rustwide/target/debug/deps/libfield_offset-d0eb0310f07de0d9.rmeta --extern lain_derive=/opt/rustwide/target/debug/deps/liblain_derive-c8ddd9bf3418c4b2.so --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-db88f49d9e5662e7.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-8b25aaf2e71705fc.rmeta --extern mashup=/opt/rustwide/target/debug/deps/libmashup-e3f0ee14ed439290.rmeta --extern num=/opt/rustwide/target/debug/deps/libnum-5c8133c7b1dd4db6.rmeta --extern num_derive=/opt/rustwide/target/debug/deps/libnum_derive-7a7bfdca29ed608a.so --extern num_traits=/opt/rustwide/target/debug/deps/libnum_traits-b5dbcc2daa2e7df6.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-79571974add4335d.rmeta --cap-lints=warn --crate-version 0.5.2` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "748477b478166af7a250ea73ca4f01a075e7097f18f46d1a68d443e94da0825f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "748477b478166af7a250ea73ca4f01a075e7097f18f46d1a68d443e94da0825f", kill_on_drop: false }`
[INFO] [stdout] 748477b478166af7a250ea73ca4f01a075e7097f18f46d1a68d443e94da0825f