[INFO] cloning repository https://github.com/zjhken/MioPractice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zjhken/MioPractice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b7e077633c9c64e7342ee2e473eea1a4421e8a49
[INFO] documenting zjhken/MioPractice against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/zjhken/MioPractice 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 git repo https://github.com/zjhken/MioPractice
[INFO] finished tweaking git repo https://github.com/zjhken/MioPractice
[INFO] tweaked toml for git repo https://github.com/zjhken/MioPractice written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/zjhken/MioPractice already has a lockfile, it will not be regenerated
[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 net2 v0.2.32
[INFO] [stderr]   Downloaded simple_logger v0.5.0
[INFO] [stderr]   Downloaded mio v0.6.14
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] 5d911d25632e102fa7586e19287e1e8014b00bfa9822a59718800f2b1dcdd50d
[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" "5d911d25632e102fa7586e19287e1e8014b00bfa9822a59718800f2b1dcdd50d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5d911d25632e102fa7586e19287e1e8014b00bfa9822a59718800f2b1dcdd50d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5d911d25632e102fa7586e19287e1e8014b00bfa9822a59718800f2b1dcdd50d", kill_on_drop: false }`
[INFO] [stdout] 5d911d25632e102fa7586e19287e1e8014b00bfa9822a59718800f2b1dcdd50d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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] 3dad31dfc02446ed01571ce59fc7eb195e280c2527e0058e59734062b1bc98c7
[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" "3dad31dfc02446ed01571ce59fc7eb195e280c2527e0058e59734062b1bc98c7", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.42
[INFO] [stderr]     Checking cfg-if v0.1.3
[INFO] [stderr]     Checking slab v0.4.0
[INFO] [stderr]     Checking lazycell v0.6.0
[INFO] [stderr]     Checking log v0.4.4
[INFO] [stderr]     Checking net2 v0.2.32
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking mio v0.6.14
[INFO] [stderr]     Checking simple_logger v0.5.0
[INFO] [stderr]     Checking MioPractice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting MioPractice 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:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(nll)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(nll)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^
[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 `MioPractice`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name MioPractice 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 log=/opt/rustwide/target/debug/deps/liblog-4a9b9be6cea611ae.rmeta --extern mio=/opt/rustwide/target/debug/deps/libmio-e185db1867c1cc38.rmeta --extern simple_logger=/opt/rustwide/target/debug/deps/libsimple_logger-37070db6959628a4.rmeta --extern slab=/opt/rustwide/target/debug/deps/libslab-81f23b9468f91613.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "3dad31dfc02446ed01571ce59fc7eb195e280c2527e0058e59734062b1bc98c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3dad31dfc02446ed01571ce59fc7eb195e280c2527e0058e59734062b1bc98c7", kill_on_drop: false }`
[INFO] [stdout] 3dad31dfc02446ed01571ce59fc7eb195e280c2527e0058e59734062b1bc98c7