[INFO] fetching crate solitaire-service 0.0.1...
[INFO] documenting solitaire-service-0.0.1 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate solitaire-service 0.0.1 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate solitaire-service 0.0.1 on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate solitaire-service 0.0.1
[INFO] finished tweaking crates.io crate solitaire-service 0.0.1
[INFO] tweaked toml for crates.io crate solitaire-service 0.0.1 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 41085b50bcfc567bd0734449bb1c8cc93ff9fcfddd7901bb6e9073db90ce964c
[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" "41085b50bcfc567bd0734449bb1c8cc93ff9fcfddd7901bb6e9073db90ce964c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "41085b50bcfc567bd0734449bb1c8cc93ff9fcfddd7901bb6e9073db90ce964c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "41085b50bcfc567bd0734449bb1c8cc93ff9fcfddd7901bb6e9073db90ce964c", kill_on_drop: false }`
[INFO] [stdout] 41085b50bcfc567bd0734449bb1c8cc93ff9fcfddd7901bb6e9073db90ce964c
[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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8c95a7264635cf6ae00453682bf78fe109e8d6ad90a90295f674a3b34022d249
[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" "8c95a7264635cf6ae00453682bf78fe109e8d6ad90a90295f674a3b34022d249", kill_on_drop: false }`
[INFO] [stderr]    Compiling slog v2.5.2
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling jobserver v0.1.21
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling derive_more v0.99.9
[INFO] [stderr]    Compiling toml v0.5.6
[INFO] [stderr]     Checking bincode v1.3.1
[INFO] [stderr]     Checking serde_json v1.0.57
[INFO] [stderr]     Checking uuid v0.8.1
[INFO] [stderr]    Compiling cc v1.0.59
[INFO] [stderr]    Compiling url v2.1.1
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling chrono v0.4.15
[INFO] [stderr]    Compiling libz-sys v1.1.1
[INFO] [stderr]    Compiling libgit2-sys v0.9.2
[INFO] [stderr]    Compiling git2 v0.10.2
[INFO] [stderr]    Compiling built v0.3.2
[INFO] [stderr]    Compiling solitaire-core v0.0.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/solitaire-core-0.0.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(option_expect_none)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/solitaire-core-0.0.1/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(fn_traits)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/solitaire-core-0.0.1/src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(unboxed_closures)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 compile `solitaire-core`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "8c95a7264635cf6ae00453682bf78fe109e8d6ad90a90295f674a3b34022d249", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c95a7264635cf6ae00453682bf78fe109e8d6ad90a90295f674a3b34022d249", kill_on_drop: false }`
[INFO] [stdout] 8c95a7264635cf6ae00453682bf78fe109e8d6ad90a90295f674a3b34022d249