[INFO] fetching crate guidon-cli 0.2.8...
[INFO] documenting guidon-cli-0.2.8 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate guidon-cli 0.2.8 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate guidon-cli 0.2.8 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate guidon-cli 0.2.8
[INFO] finished tweaking crates.io crate guidon-cli 0.2.8
[INFO] tweaked toml for crates.io crate guidon-cli 0.2.8 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate crates.io crate guidon-cli 0.2.8 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 41f3055246be73edc2191b76314166f61a740e9490a1d0d857613d98a933ed8f
[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" "41f3055246be73edc2191b76314166f61a740e9490a1d0d857613d98a933ed8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "41f3055246be73edc2191b76314166f61a740e9490a1d0d857613d98a933ed8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "41f3055246be73edc2191b76314166f61a740e9490a1d0d857613d98a933ed8f", kill_on_drop: false }`
[INFO] [stdout] 41f3055246be73edc2191b76314166f61a740e9490a1d0d857613d98a933ed8f
[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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bc30e3dd3415af9a82e0b83116023512e713b948cd10dd5221da4195ad248f0c
[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" "bc30e3dd3415af9a82e0b83116023512e713b948cd10dd5221da4195ad248f0c", kill_on_drop: false }`
[INFO] [stderr]    Compiling derive_builder v0.9.0
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]     Checking serde_json v1.0.58
[INFO] [stderr]    Compiling gumdrop_derive v0.8.0
[INFO] [stderr]     Checking toml v0.5.7
[INFO] [stderr]     Checking simple_logger v1.11.0
[INFO] [stderr]     Checking git2 v0.13.11
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]     Checking gumdrop v0.8.0
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]     Checking handlebars v3.5.0
[INFO] [stderr]    Compiling darling v0.10.2
[INFO] [stderr]    Compiling derive_builder_core v0.9.0
[INFO] [stderr]     Checking guidon v0.2.8
[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/guidon-0.2.8/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(map_first_last)]
[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 compile `guidon`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "bc30e3dd3415af9a82e0b83116023512e713b948cd10dd5221da4195ad248f0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bc30e3dd3415af9a82e0b83116023512e713b948cd10dd5221da4195ad248f0c", kill_on_drop: false }`
[INFO] [stdout] bc30e3dd3415af9a82e0b83116023512e713b948cd10dd5221da4195ad248f0c
