[INFO] fetching crate kas-gtk 0.0.2...
[INFO] documenting kas-gtk-0.0.2 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate kas-gtk 0.0.2 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate kas-gtk 0.0.2 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 kas-gtk 0.0.2
[INFO] finished tweaking crates.io crate kas-gtk 0.0.2
[INFO] tweaked toml for crates.io crate kas-gtk 0.0.2 written to /workspace/builds/worker-6/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 1c1d11703415b3c3b76fa22b4ce4478a2a1c2feffea17dc5b5cd6dd9dfbb3d5f
[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" "1c1d11703415b3c3b76fa22b4ce4478a2a1c2feffea17dc5b5cd6dd9dfbb3d5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c1d11703415b3c3b76fa22b4ce4478a2a1c2feffea17dc5b5cd6dd9dfbb3d5f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c1d11703415b3c3b76fa22b4ce4478a2a1c2feffea17dc5b5cd6dd9dfbb3d5f", kill_on_drop: false }`
[INFO] [stdout] 1c1d11703415b3c3b76fa22b4ce4478a2a1c2feffea17dc5b5cd6dd9dfbb3d5f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 868aee99ea9c8be3df421af075f3014851b28b385ca00da19d6d8354ab089dec
[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" "868aee99ea9c8be3df421af075f3014851b28b385ca00da19d6d8354ab089dec", kill_on_drop: false }`
[INFO] [stderr]    Compiling gio v0.5.1
[INFO] [stderr]     Checking fragile v0.3.0
[INFO] [stderr]    Compiling gdk-pixbuf v0.5.0
[INFO] [stderr]    Compiling cairo-rs v0.5.0
[INFO] [stderr]    Compiling gdk v0.9.0
[INFO] [stderr]    Compiling gtk v0.5.0
[INFO] [stderr]    Compiling glib-sys v0.7.0
[INFO] [stderr]    Compiling gobject-sys v0.7.0
[INFO] [stderr]    Compiling gio-sys v0.7.0
[INFO] [stderr]    Compiling cairo-sys-rs v0.7.0
[INFO] [stderr]    Compiling gdk-pixbuf-sys v0.7.0
[INFO] [stderr]    Compiling pango-sys v0.7.0
[INFO] [stderr]    Compiling gdk-sys v0.7.0
[INFO] [stderr]    Compiling atk-sys v0.7.0
[INFO] [stderr]    Compiling gtk-sys v0.7.0
[INFO] [stderr]    Compiling kas-macros v0.0.2
[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/kas-macros-0.0.2/src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(proc_macro_diagnostic)]
[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 `kas-macros`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "868aee99ea9c8be3df421af075f3014851b28b385ca00da19d6d8354ab089dec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "868aee99ea9c8be3df421af075f3014851b28b385ca00da19d6d8354ab089dec", kill_on_drop: false }`
[INFO] [stdout] 868aee99ea9c8be3df421af075f3014851b28b385ca00da19d6d8354ab089dec