[INFO] fetching crate ctre 0.6.1...
[INFO] documenting ctre-0.6.1 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate ctre 0.6.1 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate ctre 0.6.1 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 ctre 0.6.1
[INFO] finished tweaking crates.io crate ctre 0.6.1
[INFO] tweaked toml for crates.io crate ctre 0.6.1 written to /workspace/builds/worker-7/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-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] e2f0187273b7b1c767aa3b00aa8c0a0a69612a9013567f6415ba16b2be2c6804
[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" "e2f0187273b7b1c767aa3b00aa8c0a0a69612a9013567f6415ba16b2be2c6804", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e2f0187273b7b1c767aa3b00aa8c0a0a69612a9013567f6415ba16b2be2c6804", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2f0187273b7b1c767aa3b00aa8c0a0a69612a9013567f6415ba16b2be2c6804", kill_on_drop: false }`
[INFO] [stdout] e2f0187273b7b1c767aa3b00aa8c0a0a69612a9013567f6415ba16b2be2c6804
[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] 60e8c1d296fa2312168b3bcb654ed781d503f3e0bf8dfa7dd9c7a33463a60d47
[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" "60e8c1d296fa2312168b3bcb654ed781d503f3e0bf8dfa7dd9c7a33463a60d47", kill_on_drop: false }`
[INFO] [stderr]    Compiling glob v0.2.11
[INFO] [stderr]    Compiling quick-error v1.2.3
[INFO] [stderr]    Compiling regex-syntax v0.6.18
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling bindgen v0.37.4
[INFO] [stderr]    Compiling termcolor v1.1.0
[INFO] [stderr]    Compiling peeking_take_while v0.1.2
[INFO] [stderr]    Compiling ctre-sys v5.4.0
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling proc-macro2 v0.3.5
[INFO] [stderr]    Compiling libc v0.2.76
[INFO] [stderr]    Compiling aho-corasick v0.7.13
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling memchr v1.0.2
[INFO] [stderr]    Compiling which v1.0.5
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling clang-sys v0.23.0
[INFO] [stderr]    Compiling nom v3.2.1
[INFO] [stderr]    Compiling cexpr v0.2.3
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling env_logger v0.5.13
[INFO] [stderr]    Compiling wpilib-sys v0.2.3
[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/wpilib-sys-0.2.3/src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(concat_idents)]
[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 `wpilib-sys`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "60e8c1d296fa2312168b3bcb654ed781d503f3e0bf8dfa7dd9c7a33463a60d47", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60e8c1d296fa2312168b3bcb654ed781d503f3e0bf8dfa7dd9c7a33463a60d47", kill_on_drop: false }`
[INFO] [stdout] 60e8c1d296fa2312168b3bcb654ed781d503f3e0bf8dfa7dd9c7a33463a60d47