[INFO] fetching crate dns-client 0.0.2...
[INFO] documenting dns-client-0.0.2 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate dns-client 0.0.2 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate dns-client 0.0.2 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 dns-client 0.0.2
[INFO] finished tweaking crates.io crate dns-client 0.0.2
[INFO] tweaked toml for crates.io crate dns-client 0.0.2 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate crates.io crate dns-client 0.0.2 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 dnsclient v0.1.7
[INFO] [stderr]   Downloaded async-task v1.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] fcc7e7cd7c0dd8c7e5aa85e23eacd2c616b773bca3c89cec962d1d4a38dd2950
[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" "fcc7e7cd7c0dd8c7e5aa85e23eacd2c616b773bca3c89cec962d1d4a38dd2950", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fcc7e7cd7c0dd8c7e5aa85e23eacd2c616b773bca3c89cec962d1d4a38dd2950", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fcc7e7cd7c0dd8c7e5aa85e23eacd2c616b773bca3c89cec962d1d4a38dd2950", kill_on_drop: false }`
[INFO] [stdout] fcc7e7cd7c0dd8c7e5aa85e23eacd2c616b773bca3c89cec962d1d4a38dd2950
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] 2907c259c0f1868cf7a5719356947d8fb57e9a77be9d021e4cd7fb3c503367ce
[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" "2907c259c0f1868cf7a5719356947d8fb57e9a77be9d021e4cd7fb3c503367ce", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]     Checking debug-builders v0.1.0
[INFO] [stderr]    Compiling debugtrace v0.1.0
[INFO] [stderr]    Compiling memchr v2.3.0
[INFO] [stderr]     Checking either v0.1.7
[INFO] [stderr]     Checking hex v0.4.0
[INFO] [stderr]     Checking futures-timer v2.0.2
[INFO] [stderr]     Checking futures-core v0.3.1
[INFO] [stderr]     Checking futures-io v0.3.1
[INFO] [stderr]    Compiling dbghelp-sys v0.2.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling crossbeam-utils v0.7.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.0
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]     Checking conv v0.3.3
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.12.0
[INFO] [stderr]     Checking async-task v1.3.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking crossbeam-channel v0.4.0
[INFO] [stderr]     Checking backtrace v0.1.8
[INFO] [stderr]     Checking crossbeam-deque v0.7.2
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]     Checking async-std v1.4.0
[INFO] [stderr]     Checking chomp v0.3.1
[INFO] [stderr]    Compiling thiserror-impl v1.0.10
[INFO] [stderr]    Compiling rustversion v1.0.2
[INFO] [stderr]     Checking thiserror v1.0.10
[INFO] [stderr]     Checking dnssector v0.2.0
[INFO] [stderr]     Checking dnsclient v0.1.7
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/dnsclient-0.1.7/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_hygiene)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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: could not compile `dnsclient`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "2907c259c0f1868cf7a5719356947d8fb57e9a77be9d021e4cd7fb3c503367ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2907c259c0f1868cf7a5719356947d8fb57e9a77be9d021e4cd7fb3c503367ce", kill_on_drop: false }`
[INFO] [stdout] 2907c259c0f1868cf7a5719356947d8fb57e9a77be9d021e4cd7fb3c503367ce