[INFO] cloning repository https://github.com/R4chel/art
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/R4chel/art" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FR4chel%2Fart", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FR4chel%2Fart'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9afcd6660e4f76df8f2df2000c46aa1240cbe1ea
[INFO] testing R4chel/art against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FR4chel%2Fart" "/workspace/builds/worker-101/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-101/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/R4chel/art on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/R4chel/art
[INFO] finished tweaking git repo https://github.com/R4chel/art
[INFO] tweaked toml for git repo https://github.com/R4chel/art written to /workspace/builds/worker-101/source/Cargo.toml
[INFO] crate git repo https://github.com/R4chel/art already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded hsl v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0b0bde91d3e6e0841f3424339975feefe7b33865cf5490229731f2bbd9d89105
[INFO] running `Command { std: "docker" "start" "-a" "0b0bde91d3e6e0841f3424339975feefe7b33865cf5490229731f2bbd9d89105", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0b0bde91d3e6e0841f3424339975feefe7b33865cf5490229731f2bbd9d89105", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0b0bde91d3e6e0841f3424339975feefe7b33865cf5490229731f2bbd9d89105", kill_on_drop: false }`
[INFO] [stdout] 0b0bde91d3e6e0841f3424339975feefe7b33865cf5490229731f2bbd9d89105
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-101/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" "RUSTFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 54991aed4721cf558100dcab57967a7cdb3b190695d32b3024b64f4ebe174d6c
[INFO] running `Command { std: "docker" "start" "-a" "54991aed4721cf558100dcab57967a7cdb3b190695d32b3024b64f4ebe174d6c", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.71
[INFO] [stderr]    Compiling libc v0.2.87
[INFO] [stderr]    Compiling bumpalo v3.6.1
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling wasm-bindgen v0.2.71
[INFO] [stderr]    Compiling hsl v0.1.1
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.71
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.71
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.71
[INFO] [stderr]    Compiling js-sys v0.3.48
[INFO] [stderr]    Compiling web-sys v0.3.48
[INFO] [stderr]    Compiling art v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(drain_filter)]
[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 `art` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "54991aed4721cf558100dcab57967a7cdb3b190695d32b3024b64f4ebe174d6c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54991aed4721cf558100dcab57967a7cdb3b190695d32b3024b64f4ebe174d6c", kill_on_drop: false }`
[INFO] [stdout] 54991aed4721cf558100dcab57967a7cdb3b190695d32b3024b64f4ebe174d6c