[INFO] cloning repository https://github.com/dagit/emu-test
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dagit/emu-test" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdagit%2Femu-test", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdagit%2Femu-test'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f019c9551ff008e79e619f3c7fbd81da3823fbf6
[INFO] documenting dagit/emu-test against 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdagit%2Femu-test" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dagit/emu-test 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 git repo https://github.com/dagit/emu-test
[INFO] finished tweaking git repo https://github.com/dagit/emu-test
[INFO] tweaked toml for git repo https://github.com/dagit/emu-test written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/dagit/emu-test already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded genawaiter v0.99.1
[INFO] [stderr]   Downloaded genawaiter-macro v0.99.1
[INFO] [stderr]   Downloaded genawaiter-proc-macro v0.99.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 61d1da6f09e63b014a25d4716b1ce2f8cef5f1ef7aa59af71bbc50d1ee2d96f9
[INFO] running `Command { std: "docker" "start" "-a" "61d1da6f09e63b014a25d4716b1ce2f8cef5f1ef7aa59af71bbc50d1ee2d96f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "61d1da6f09e63b014a25d4716b1ce2f8cef5f1ef7aa59af71bbc50d1ee2d96f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "61d1da6f09e63b014a25d4716b1ce2f8cef5f1ef7aa59af71bbc50d1ee2d96f9", kill_on_drop: false }`
[INFO] [stdout] 61d1da6f09e63b014a25d4716b1ce2f8cef5f1ef7aa59af71bbc50d1ee2d96f9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] 31c298e9b500e4c44083de92cecc26b591babb2dd7e8dda1019cfe2faa2f9b65
[INFO] running `Command { std: "docker" "start" "-a" "31c298e9b500e4c44083de92cecc26b591babb2dd7e8dda1019cfe2faa2f9b65", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.10
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]    Compiling version_check v0.9.1
[INFO] [stderr]     Checking futures-core v0.3.4
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling proc-macro-hack v0.5.15
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling proc-macro-nested v0.1.4
[INFO] [stderr]     Checking futures-io v0.3.4
[INFO] [stderr]     Checking futures-sink v0.3.4
[INFO] [stderr]     Checking futures-task v0.3.4
[INFO] [stderr]     Checking pin-project-lite v0.1.4
[INFO] [stderr]     Checking once_cell v1.3.1
[INFO] [stderr]     Checking futures-timer v2.0.2
[INFO] [stderr]     Checking bytes v0.5.4
[INFO] [stderr]     Checking genawaiter-macro v0.99.1
[INFO] [stderr]     Checking futures-channel v0.3.4
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.4
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.12
[INFO] [stderr]    Compiling proc-macro-error v0.4.12
[INFO] [stderr]     Checking kv-log-macro v1.0.4
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking async-task v1.3.1
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking crossbeam-channel v0.4.2
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]     Checking async-std v1.5.0
[INFO] [stderr]    Compiling syn-mid v0.5.0
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]     Checking tokio v0.2.19
[INFO] [stderr]     Checking futures-util v0.3.4
[INFO] [stderr]    Compiling genawaiter-proc-macro v0.99.1
[INFO] [stderr]     Checking genawaiter v0.99.1
[INFO] [stderr]     Checking futures-executor v0.3.4
[INFO] [stderr]     Checking futures v0.3.4
[INFO] [stderr]  Documenting emu-test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(generators, generator_trait)]
[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 `emu-test`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name emu_test src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=ffa68e6caace75f6 -L dependency=/opt/rustwide/target/debug/deps --extern async_std=/opt/rustwide/target/debug/deps/libasync_std-90661de1ae1a8af1.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-86b7d55d5086abc0.rmeta --extern genawaiter=/opt/rustwide/target/debug/deps/libgenawaiter-29b5825475e0e411.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-86ea595a6e8e53e1.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "31c298e9b500e4c44083de92cecc26b591babb2dd7e8dda1019cfe2faa2f9b65", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31c298e9b500e4c44083de92cecc26b591babb2dd7e8dda1019cfe2faa2f9b65", kill_on_drop: false }`
[INFO] [stdout] 31c298e9b500e4c44083de92cecc26b591babb2dd7e8dda1019cfe2faa2f9b65