[INFO] cloning repository https://github.com/chankyin/fstree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/chankyin/fstree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchankyin%2Ffstree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchankyin%2Ffstree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 11576f11f6258048a449ad2cebaf35ca8f2d79c6
[INFO] documenting chankyin/fstree against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchankyin%2Ffstree" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/chankyin/fstree on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/chankyin/fstree
[INFO] finished tweaking git repo https://github.com/chankyin/fstree
[INFO] tweaked toml for git repo https://github.com/chankyin/fstree written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/chankyin/fstree already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 56ae1c3890042f63f91bb58348c33f5919b75902fd629bce74d170668d56cf0c
[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" "56ae1c3890042f63f91bb58348c33f5919b75902fd629bce74d170668d56cf0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "56ae1c3890042f63f91bb58348c33f5919b75902fd629bce74d170668d56cf0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56ae1c3890042f63f91bb58348c33f5919b75902fd629bce74d170668d56cf0c", kill_on_drop: false }`
[INFO] [stdout] 56ae1c3890042f63f91bb58348c33f5919b75902fd629bce74d170668d56cf0c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 59296d4c8f9b0589d1a2b92e11b2bb406f18ae123df520fc721fe873e8a7e9ca
[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" "59296d4c8f9b0589d1a2b92e11b2bb406f18ae123df520fc721fe873e8a7e9ca", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.2
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling getrandom v0.1.11
[INFO] [stderr]     Checking regex-syntax v0.6.11
[INFO] [stderr]    Compiling serde v1.0.99
[INFO] [stderr]     Checking filesize v0.1.0
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking tracing-core v0.1.5
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking tokio-io v0.2.0-alpha.4
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking tokio-codec v0.2.0-alpha.4
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking rand v0.7.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking regex v1.2.1
[INFO] [stderr]     Checking tokio-sync v0.2.0-alpha.4
[INFO] [stderr]     Checking console v0.8.0
[INFO] [stderr]     Checking indicatif v0.11.0
[INFO] [stderr]     Checking dialoguer v0.4.0
[INFO] [stderr]    Compiling tracing-attributes v0.1.2
[INFO] [stderr]    Compiling tokio-macros v0.2.0-alpha.4
[INFO] [stderr]    Compiling serde_derive v1.0.99
[INFO] [stderr]     Checking tracing v0.1.7
[INFO] [stderr]     Checking tokio-executor v0.2.0-alpha.4
[INFO] [stderr]     Checking tokio-timer v0.3.0-alpha.4
[INFO] [stderr]     Checking tokio-fs v0.2.0-alpha.4
[INFO] [stderr]     Checking tokio-net v0.2.0-alpha.4
[INFO] [stderr]     Checking tokio v0.2.0-alpha.4
[INFO] [stderr]  Documenting fstree 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(async_closure)]
[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 `fstree`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name fstree src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern dialoguer=/opt/rustwide/target/debug/deps/libdialoguer-f9b4186fbed10b22.rmeta --extern filesize=/opt/rustwide/target/debug/deps/libfilesize-b897dc96193ed0be.rmeta --extern futures_util=/opt/rustwide/target/debug/deps/libfutures_util-c3cdee9755592627.rmeta --extern indicatif=/opt/rustwide/target/debug/deps/libindicatif-bafbf024e38a9752.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-0ffd35a54dcc8a9b.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-c48d94c35d5a9dbb.rmeta --extern tokio_executor=/opt/rustwide/target/debug/deps/libtokio_executor-072b9fd9efb48f5a.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "59296d4c8f9b0589d1a2b92e11b2bb406f18ae123df520fc721fe873e8a7e9ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59296d4c8f9b0589d1a2b92e11b2bb406f18ae123df520fc721fe873e8a7e9ca", kill_on_drop: false }`
[INFO] [stdout] 59296d4c8f9b0589d1a2b92e11b2bb406f18ae123df520fc721fe873e8a7e9ca