[INFO] fetching crate enso-prelude 0.2.6...
[INFO] testing enso-prelude-0.2.6 against 1.55.0 for beta-1.56-1
[INFO] extracting crate enso-prelude 0.2.6 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate enso-prelude 0.2.6 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 crates.io crate enso-prelude 0.2.6
[INFO] finished tweaking crates.io crate enso-prelude 0.2.6
[INFO] tweaked toml for crates.io crate enso-prelude 0.2.6 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 9bba3fe536d7ee71464c44233fac8acc6f264a13ab77ed9481e5f86420604326
[INFO] running `Command { std: "docker" "start" "-a" "9bba3fe536d7ee71464c44233fac8acc6f264a13ab77ed9481e5f86420604326", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9bba3fe536d7ee71464c44233fac8acc6f264a13ab77ed9481e5f86420604326", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9bba3fe536d7ee71464c44233fac8acc6f264a13ab77ed9481e5f86420604326", kill_on_drop: false }`
[INFO] [stdout] 9bba3fe536d7ee71464c44233fac8acc6f264a13ab77ed9481e5f86420604326
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] da81fce38bd8a41330ec1599b3d365d81ff8b1a852489c34c6b79b56065b118f
[INFO] running `Command { std: "docker" "start" "-a" "da81fce38bd8a41330ec1599b3d365d81ff8b1a852489c34c6b79b56065b118f", kill_on_drop: false }`
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.58
[INFO] [stderr]    Compiling bumpalo v3.7.0
[INFO] [stderr]    Compiling wasm-bindgen v0.2.58
[INFO] [stderr]    Compiling rustversion v1.0.5
[INFO] [stderr]    Compiling sourcefile v0.1.4
[INFO] [stderr]    Compiling weak-table v0.3.0
[INFO] [stderr]    Compiling enclose v1.1.8
[INFO] [stderr]    Compiling num-bigint v0.4.2
[INFO] [stderr]    Compiling matrixmultiply v0.3.1
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-complex v0.3.1
[INFO] [stderr]    Compiling approx v0.4.0
[INFO] [stderr]    Compiling num-complex v0.4.0
[INFO] [stderr]    Compiling weedle v0.10.0
[INFO] [stderr]    Compiling backtrace v0.3.61
[INFO] [stderr]    Compiling enso-macro-utils v0.2.0
[INFO] [stderr]    Compiling shrinkwraprs v0.3.0
[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/enso-macro-utils-0.2.0/src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling derivative v2.2.0
[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 `enso-macro-utils` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "da81fce38bd8a41330ec1599b3d365d81ff8b1a852489c34c6b79b56065b118f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da81fce38bd8a41330ec1599b3d365d81ff8b1a852489c34c6b79b56065b118f", kill_on_drop: false }`
[INFO] [stdout] da81fce38bd8a41330ec1599b3d365d81ff8b1a852489c34c6b79b56065b118f