[INFO] fetching crate descent_ipopt 0.4.0...
[INFO] documenting descent_ipopt-0.4.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate descent_ipopt 0.4.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate descent_ipopt 0.4.0 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 descent_ipopt 0.4.0
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate descent_ipopt 0.4.0
[INFO] tweaked toml for crates.io crate descent_ipopt 0.4.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate crates.io crate descent_ipopt 0.4.0 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]  Downloading crates ...
[INFO] [stderr]   Downloaded descent_macro v0.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] c7196933c6d19b60c3d869cd284a0aaff2d0523033b7399eec022df1ef3662d1
[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" "c7196933c6d19b60c3d869cd284a0aaff2d0523033b7399eec022df1ef3662d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c7196933c6d19b60c3d869cd284a0aaff2d0523033b7399eec022df1ef3662d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c7196933c6d19b60c3d869cd284a0aaff2d0523033b7399eec022df1ef3662d1", kill_on_drop: false }`
[INFO] [stdout] c7196933c6d19b60c3d869cd284a0aaff2d0523033b7399eec022df1ef3662d1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] c2b7645d333d38525b8e8984fa4b54a85b274e8890ca81fe57e976cf530ff205
[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" "c2b7645d333d38525b8e8984fa4b54a85b274e8890ca81fe57e976cf530ff205", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.27
[INFO] [stderr]    Compiling doc-comment v0.3.3
[INFO] [stderr]    Compiling snafu-derive v0.6.8
[INFO] [stderr]     Checking snafu v0.6.8
[INFO] [stderr]     Checking descent v0.4.0
[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/descent-0.4.0/src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(test)] // enable benchmarking
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `descent`.
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "c2b7645d333d38525b8e8984fa4b54a85b274e8890ca81fe57e976cf530ff205", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c2b7645d333d38525b8e8984fa4b54a85b274e8890ca81fe57e976cf530ff205", kill_on_drop: false }`
[INFO] [stdout] c2b7645d333d38525b8e8984fa4b54a85b274e8890ca81fe57e976cf530ff205