[INFO] updating cached repository myelin-ai/engine
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/myelin-ai/engine
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/myelin-ai/engine" "work/ex/beta-1.38-1/sources/1.37.0/gh/myelin-ai/engine"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/myelin-ai/engine'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/myelin-ai/engine" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/myelin-ai/engine"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/myelin-ai/engine'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 019866caa63fc505db216d1eab80f24129aa5436
[INFO] sha for GitHub repo myelin-ai/engine: 019866caa63fc505db216d1eab80f24129aa5436
[INFO] validating manifest of myelin-ai/engine on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of myelin-ai/engine on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing myelin-ai/engine
[INFO] finished frobbing myelin-ai/engine
[INFO] frobbed toml for myelin-ai/engine written to work/ex/beta-1.38-1/sources/1.37.0/gh/myelin-ai/engine/Cargo.toml
[INFO] started frobbing myelin-ai/engine
[INFO] finished frobbing myelin-ai/engine
[INFO] frobbed toml for myelin-ai/engine written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/myelin-ai/engine/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing myelin-ai/engine against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/myelin-ai/engine:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 3f1f8bb79ad16bc86a034106e5306c3f43f60aef516d03b7fba6f8fa56763071
[INFO] running `"docker" "start" "-a" "3f1f8bb79ad16bc86a034106e5306c3f43f60aef516d03b7fba6f8fa56763071"`
[INFO] [stderr]    Compiling nameof v1.1.0
[INFO] [stderr]    Compiling alga v0.9.1
[INFO] [stderr]    Compiling serde v1.0.99
[INFO] [stderr]    Compiling nalgebra v0.18.0
[INFO] [stderr]    Compiling myelin-geometry v2.4.0
[INFO] [stderr]    Compiling ncollide2d v0.19.2
[INFO] [stderr]    Compiling nphysics2d v0.11.1
[INFO] [stderr]    Compiling myelin-engine v0.13.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta 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 beta 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 beta 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 beta 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" "3f1f8bb79ad16bc86a034106e5306c3f43f60aef516d03b7fba6f8fa56763071"`
[INFO] running `"docker" "rm" "-f" "3f1f8bb79ad16bc86a034106e5306c3f43f60aef516d03b7fba6f8fa56763071"`
[INFO] [stdout] 3f1f8bb79ad16bc86a034106e5306c3f43f60aef516d03b7fba6f8fa56763071