[INFO] cloning repository https://github.com/Aaron1011/for-await-test
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Aaron1011/for-await-test" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAaron1011%2Ffor-await-test", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAaron1011%2Ffor-await-test'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 917745507864a842d2ec6b928621ff2353db8810
[INFO] documenting Aaron1011/for-await-test 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%2FAaron1011%2Ffor-await-test" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Aaron1011/for-await-test 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/Aaron1011/for-await-test
[INFO] finished tweaking git repo https://github.com/Aaron1011/for-await-test
[INFO] tweaked toml for git repo https://github.com/Aaron1011/for-await-test written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/Aaron1011/for-await-test 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]     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 futures-async-stream-macro v0.1.3
[INFO] [stderr]   Downloaded futures-async-stream v0.1.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 9fe630824ee2931a665963f6da9eb864ada9d8d5405fee7deb9e841cbdb0a9f2
[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" "9fe630824ee2931a665963f6da9eb864ada9d8d5405fee7deb9e841cbdb0a9f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9fe630824ee2931a665963f6da9eb864ada9d8d5405fee7deb9e841cbdb0a9f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9fe630824ee2931a665963f6da9eb864ada9d8d5405fee7deb9e841cbdb0a9f2", kill_on_drop: false }`
[INFO] [stdout] 9fe630824ee2931a665963f6da9eb864ada9d8d5405fee7deb9e841cbdb0a9f2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] aab41b36d7b50861d9b69ee88dd87b3332ecf7ea8c129709b40f6d9d7a4fcca9
[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" "aab41b36d7b50861d9b69ee88dd87b3332ecf7ea8c129709b40f6d9d7a4fcca9", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.16
[INFO] [stderr]     Checking futures-core v0.3.4
[INFO] [stderr]     Checking futures-sink v0.3.4
[INFO] [stderr]    Compiling proc-macro2 v1.0.9
[INFO] [stderr]     Checking futures-channel v0.3.4
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]    Compiling proc-macro-hack v0.5.12
[INFO] [stderr]    Compiling pin-project-internal v0.4.8
[INFO] [stderr]    Compiling futures-async-stream-macro v0.1.3
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]     Checking pin-project v0.4.8
[INFO] [stderr]     Checking futures-async-stream v0.1.3
[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/futures-async-stream-0.1.3/src/lib.rs:217:1
[INFO] [stdout]     |
[INFO] [stdout] 217 | #![feature(generator_trait)]
[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 `futures-async-stream`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "aab41b36d7b50861d9b69ee88dd87b3332ecf7ea8c129709b40f6d9d7a4fcca9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aab41b36d7b50861d9b69ee88dd87b3332ecf7ea8c129709b40f6d9d7a4fcca9", kill_on_drop: false }`
[INFO] [stdout] aab41b36d7b50861d9b69ee88dd87b3332ecf7ea8c129709b40f6d9d7a4fcca9