[INFO] cloning repository https://github.com/avr-rust/blink
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/avr-rust/blink" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Favr-rust%2Fblink", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Favr-rust%2Fblink'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7c58f52a3c1f829215235d9b1c91e42346dd2cf6
[INFO] documenting avr-rust/blink against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Favr-rust%2Fblink" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/avr-rust/blink 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 git repo https://github.com/avr-rust/blink
[INFO] finished tweaking git repo https://github.com/avr-rust/blink
[INFO] tweaked toml for git repo https://github.com/avr-rust/blink written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/avr-rust/blink already has a lockfile, it will not be regenerated
[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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 7b7c0c14fe1674c2cd06abb7f9b812c3bf576bf8f18d867b877416f16f68f76c
[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" "7b7c0c14fe1674c2cd06abb7f9b812c3bf576bf8f18d867b877416f16f68f76c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7b7c0c14fe1674c2cd06abb7f9b812c3bf576bf8f18d867b877416f16f68f76c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b7c0c14fe1674c2cd06abb7f9b812c3bf576bf8f18d867b877416f16f68f76c", kill_on_drop: false }`
[INFO] [stdout] 7b7c0c14fe1674c2cd06abb7f9b812c3bf576bf8f18d867b877416f16f68f76c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 3e9f75f106d5f12a4e84cd6401752126ed8537bb073c9e319a617f759135dcfb
[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" "3e9f75f106d5f12a4e84cd6401752126ed8537bb073c9e319a617f759135dcfb", kill_on_drop: false }`
[INFO] [stderr]    Compiling xml-rs v0.4.1
[INFO] [stderr]    Compiling xmltree v0.4.0
[INFO] [stderr]    Compiling avr-mcu v0.2.6
[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/avr-mcu-0.2.6/src/lib.rs:38:1
[INFO] [stdout]    |
[INFO] [stdout] 38 | #![feature(conservative_impl_trait)]
[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 `avr-mcu`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "3e9f75f106d5f12a4e84cd6401752126ed8537bb073c9e319a617f759135dcfb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3e9f75f106d5f12a4e84cd6401752126ed8537bb073c9e319a617f759135dcfb", kill_on_drop: false }`
[INFO] [stdout] 3e9f75f106d5f12a4e84cd6401752126ed8537bb073c9e319a617f759135dcfb