[INFO] updating cached repository https://github.com/myelin-ai/engine
[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] 0457e868357cef6916418e9674807b6988414444
[INFO] testing myelin-ai/engine against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmyelin-ai%2Fengine" "work/builds/worker-3/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/myelin-ai/engine 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/myelin-ai/engine
[INFO] finished tweaking git repo https://github.com/myelin-ai/engine
[INFO] tweaked toml for git repo https://github.com/myelin-ai/engine written to work/builds/worker-3/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-3/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-3/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] 208aead40a2ee49a132bf6b12fbbe9104554f1d680b7cc41e9fe24f155c7bcc8
[INFO] running `"docker" "start" "-a" "208aead40a2ee49a132bf6b12fbbe9104554f1d680b7cc41e9fe24f155c7bcc8"`
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling rawpointer v0.2.1
[INFO] [stderr]    Compiling slotmap v0.3.0
[INFO] [stderr]    Compiling nameof v1.1.0
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling itertools v0.8.0
[INFO] [stderr]    Compiling generational-arena v0.2.3
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling matrixmultiply v0.2.3
[INFO] [stderr]    Compiling alga v0.9.1
[INFO] [stderr]    Compiling nalgebra v0.18.1
[INFO] [stderr]    Compiling serde_derive v1.0.101
[INFO] [stderr]    Compiling serde v1.0.101
[INFO] [stderr]    Compiling myelin-geometry v2.4.0
[INFO] [stderr]    Compiling ncollide2d v0.20.1
[INFO] [stderr]    Compiling nphysics2d v0.12.3
[INFO] [stderr]    Compiling myelin-engine v0.14.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | #![feature(specialization)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![feature(non_exhaustive)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:7:1
[INFO] [stderr]   |
[INFO] [stderr] 7 | #![feature(box_syntax)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:8:1
[INFO] [stderr]   |
[INFO] [stderr] 8 | #![feature(trait_alias)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `myelin-engine`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "208aead40a2ee49a132bf6b12fbbe9104554f1d680b7cc41e9fe24f155c7bcc8"`
[INFO] running `"docker" "rm" "-f" "208aead40a2ee49a132bf6b12fbbe9104554f1d680b7cc41e9fe24f155c7bcc8"`
[INFO] [stdout] 208aead40a2ee49a132bf6b12fbbe9104554f1d680b7cc41e9fe24f155c7bcc8