[INFO] cloning repository https://github.com/mythmon/rearguard
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mythmon/rearguard" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmythmon%2Frearguard", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmythmon%2Frearguard'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7fde477fcbc072af8d710874018045a6a1793903
[INFO] documenting mythmon/rearguard against beta-2022-05-20 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmythmon%2Frearguard" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mythmon/rearguard on toolchain beta-2022-05-20
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-05-20" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mythmon/rearguard
[INFO] finished tweaking git repo https://github.com/mythmon/rearguard
[INFO] tweaked toml for git repo https://github.com/mythmon/rearguard written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/mythmon/rearguard already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-05-20" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "+beta-2022-05-20" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 93237771d698964844a772cdf36cd71f241a2237d3d5d9c9587c6072b4fa04ab
[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" "93237771d698964844a772cdf36cd71f241a2237d3d5d9c9587c6072b4fa04ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "93237771d698964844a772cdf36cd71f241a2237d3d5d9c9587c6072b4fa04ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "93237771d698964844a772cdf36cd71f241a2237d3d5d9c9587c6072b4fa04ab", kill_on_drop: false }`
[INFO] [stdout] 93237771d698964844a772cdf36cd71f241a2237d3d5d9c9587c6072b4fa04ab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "+beta-2022-05-20" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] bb6844db09648da4a23f019808b7e83219a5456a9e31458dc2f80b0c607e8cd2
[INFO] running `Command { std: "docker" "start" "-a" "bb6844db09648da4a23f019808b7e83219a5456a9e31458dc2f80b0c607e8cd2", kill_on_drop: false }`
[INFO] [stderr]  Documenting rearguard v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: cannot find macro `select` in this scope
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |         select! (
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: cannot find macro `select` in this scope
[INFO] [stdout]   --> src/main.rs:89:9
[INFO] [stdout]    |
[INFO] [stdout] 89 |         select! (
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(collections)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(plugin)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(std_misc)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 6 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 `rearguard`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name rearguard src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items '-Arustdoc::private-intra-doc-links' -C metadata=49449bed322c350e -L dependency=/opt/rustwide/target/debug/deps --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "bb6844db09648da4a23f019808b7e83219a5456a9e31458dc2f80b0c607e8cd2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb6844db09648da4a23f019808b7e83219a5456a9e31458dc2f80b0c607e8cd2", kill_on_drop: false }`
[INFO] [stdout] bb6844db09648da4a23f019808b7e83219a5456a9e31458dc2f80b0c607e8cd2