[INFO] fetching crate semaphorus 0.2.1...
[INFO] documenting semaphorus-0.2.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate semaphorus 0.2.1 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate semaphorus 0.2.1 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate semaphorus 0.2.1
[INFO] finished tweaking crates.io crate semaphorus 0.2.1
[INFO] tweaked toml for crates.io crate semaphorus 0.2.1 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 22b6206ab724d8ee27ce99ac65b5daa5914aa6d3cac76cc92e7fb0af409490cf
[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" "22b6206ab724d8ee27ce99ac65b5daa5914aa6d3cac76cc92e7fb0af409490cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "22b6206ab724d8ee27ce99ac65b5daa5914aa6d3cac76cc92e7fb0af409490cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22b6206ab724d8ee27ce99ac65b5daa5914aa6d3cac76cc92e7fb0af409490cf", kill_on_drop: false }`
[INFO] [stdout] 22b6206ab724d8ee27ce99ac65b5daa5914aa6d3cac76cc92e7fb0af409490cf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e0750b9082432a23e43b49b7aa689001b7791280776407ec4acb5d6917d42590
[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" "e0750b9082432a23e43b49b7aa689001b7791280776407ec4acb5d6917d42590", kill_on_drop: false }`
[INFO] [stderr]  Documenting semaphorus v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:44
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(any(feature = "nightly", doc), feature(negative_impls))]
[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 `semaphorus`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2021 --crate-type lib --crate-name semaphorus src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="std"' --cfg 'feature="wrapper"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=d965a493c3ff6216 -L dependency=/opt/rustwide/target/debug/deps --cap-lints=warn --crate-version 0.2.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "e0750b9082432a23e43b49b7aa689001b7791280776407ec4acb5d6917d42590", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e0750b9082432a23e43b49b7aa689001b7791280776407ec4acb5d6917d42590", kill_on_drop: false }`
[INFO] [stdout] e0750b9082432a23e43b49b7aa689001b7791280776407ec4acb5d6917d42590