[INFO] updating cached repository https://github.com/FrozenDroid/serialmonitor-rust
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 82625c794fc9bb30fc24a2817f1c67f186bfbba8
[INFO] testing FrozenDroid/serialmonitor-rust against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2FFrozenDroid%2Fserialmonitor-rust" "work/builds/worker-1/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/FrozenDroid/serialmonitor-rust on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/FrozenDroid/serialmonitor-rust
[INFO] finished tweaking git repo https://github.com/FrozenDroid/serialmonitor-rust
[INFO] tweaked toml for git repo https://github.com/FrozenDroid/serialmonitor-rust written to work/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/FrozenDroid/serialmonitor-rust already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-1/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 4c6bf9989547bfb052512d8e84eaf08f33a561ede58fa3b88bbb2ccd6ae94481
[INFO] running `"docker" "start" "-a" "4c6bf9989547bfb052512d8e84eaf08f33a561ede58fa3b88bbb2ccd6ae94481"`
[INFO] [stderr]    Compiling gio v0.3.0
[INFO] [stderr]    Compiling cairo-rs v0.3.0
[INFO] [stderr]    Compiling gdk-pixbuf v0.3.0
[INFO] [stderr]    Compiling gdk v0.7.0
[INFO] [stderr]    Compiling gtk v0.3.0
[INFO] [stderr]    Compiling glib-sys v0.5.0
[INFO] [stderr]    Compiling gobject-sys v0.5.0
[INFO] [stderr]    Compiling gio-sys v0.5.0
[INFO] [stderr]    Compiling pango-sys v0.5.0
[INFO] [stderr]    Compiling gdk-pixbuf-sys v0.5.0
[INFO] [stderr]    Compiling cairo-sys-rs v0.5.0
[INFO] [stderr]    Compiling gdk-sys v0.5.0
[INFO] [stderr]    Compiling atk-sys v0.5.0
[INFO] [stderr]    Compiling gtk-sys v0.5.0
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling env_logger v0.4.3
[INFO] [stderr]    Compiling futures-glib v0.3.2
[INFO] [stderr]    Compiling glib v0.4.1
[INFO] [stderr]    Compiling relm-core v0.11.0
[INFO] [stderr]    Compiling relm-state v0.11.0
[INFO] [stderr]    Compiling relm-gen-widget v0.11.0
[INFO] [stderr]    Compiling relm-derive-common v0.11.0
[INFO] [stderr]    Compiling pango v0.3.0
[INFO] [stderr]    Compiling relm-attributes v0.11.0
[INFO] [stderr]    Compiling relm-derive v0.11.0
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/relm-attributes-0.11.0/src/lib.rs:22:1
[INFO] [stderr]    |
[INFO] [stderr] 22 | #![feature(proc_macro)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `relm-attributes`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "4c6bf9989547bfb052512d8e84eaf08f33a561ede58fa3b88bbb2ccd6ae94481"`
[INFO] running `"docker" "rm" "-f" "4c6bf9989547bfb052512d8e84eaf08f33a561ede58fa3b88bbb2ccd6ae94481"`
[INFO] [stdout] 4c6bf9989547bfb052512d8e84eaf08f33a561ede58fa3b88bbb2ccd6ae94481