[INFO] cloning repository https://github.com/xsznix/keygen
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/xsznix/keygen" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxsznix%2Fkeygen", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxsznix%2Fkeygen'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 13551be7775a8ee75e2713958488c482e56a0e4e
[INFO] documenting xsznix/keygen against 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxsznix%2Fkeygen" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xsznix/keygen 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 git repo https://github.com/xsznix/keygen
[INFO] finished tweaking git repo https://github.com/xsznix/keygen
[INFO] tweaked toml for git repo https://github.com/xsznix/keygen written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/xsznix/keygen already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rand v0.3.12
[INFO] [stderr]   Downloaded libc v0.2.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] 6b99778a34ab821f4660aa9c2285527df9c0ce84590812bba89a650538d87449
[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" "6b99778a34ab821f4660aa9c2285527df9c0ce84590812bba89a650538d87449", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b99778a34ab821f4660aa9c2285527df9c0ce84590812bba89a650538d87449", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b99778a34ab821f4660aa9c2285527df9c0ce84590812bba89a650538d87449", kill_on_drop: false }`
[INFO] [stdout] 6b99778a34ab821f4660aa9c2285527df9c0ce84590812bba89a650538d87449
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d4257f6af9d7f3837d5a16ada47c323613f573af1e03d8a69264db340aca8e78
[INFO] running `Command { std: "docker" "start" "-a" "d4257f6af9d7f3837d5a16ada47c323613f573af1e03d8a69264db340aca8e78", kill_on_drop: false }`
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]     Checking winapi v0.2.5
[INFO] [stderr]     Checking libc v0.2.4
[INFO] [stderr]     Checking unicode-width v0.1.9
[INFO] [stderr]     Checking getopts v0.2.21
[INFO] [stderr]    Compiling advapi32-sys v0.1.2
[INFO] [stderr]     Checking rand v0.3.12
[INFO] [stderr]  Documenting keygen v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:13
[INFO] [stdout]   |
[INFO] [stdout] 1 |  #![feature(linked_list_cursors)]
[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 document `keygen`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name keygen src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=e3eb9d8d68be7668 -L dependency=/opt/rustwide/target/debug/deps --extern getopts=/opt/rustwide/target/debug/deps/libgetopts-cdbb25a934be796f.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-1423d2698c17ffdd.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "d4257f6af9d7f3837d5a16ada47c323613f573af1e03d8a69264db340aca8e78", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d4257f6af9d7f3837d5a16ada47c323613f573af1e03d8a69264db340aca8e78", kill_on_drop: false }`
[INFO] [stdout] d4257f6af9d7f3837d5a16ada47c323613f573af1e03d8a69264db340aca8e78