[INFO] updating cached repository luciusmagn/ipc-rs
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/luciusmagn/ipc-rs
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/luciusmagn/ipc-rs" "work/ex/beta-1.38-1/sources/1.37.0/gh/luciusmagn/ipc-rs"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/luciusmagn/ipc-rs'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/luciusmagn/ipc-rs" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/luciusmagn/ipc-rs"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/luciusmagn/ipc-rs'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e6179c538f1e1d7bbcdc17f745757fede29c4dc8
[INFO] sha for GitHub repo luciusmagn/ipc-rs: e6179c538f1e1d7bbcdc17f745757fede29c4dc8
[INFO] validating manifest of luciusmagn/ipc-rs 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 luciusmagn/ipc-rs 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 luciusmagn/ipc-rs
[INFO] finished frobbing luciusmagn/ipc-rs
[INFO] frobbed toml for luciusmagn/ipc-rs written to work/ex/beta-1.38-1/sources/1.37.0/gh/luciusmagn/ipc-rs/Cargo.toml
[INFO] started frobbing luciusmagn/ipc-rs
[INFO] finished frobbing luciusmagn/ipc-rs
[INFO] frobbed toml for luciusmagn/ipc-rs written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/luciusmagn/ipc-rs/Cargo.toml
[INFO] crate luciusmagn/ipc-rs already has a lockfile, it will not be regenerated
[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 luciusmagn/ipc-rs 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-1/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/luciusmagn/ipc-rs:/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] 0ad7896aab2755324cab50768952fc793ccf489daa050a8fe2b401684839cc14
[INFO] running `"docker" "start" "-a" "0ad7896aab2755324cab50768952fc793ccf489daa050a8fe2b401684839cc14"`
[INFO] [stderr]    Compiling serde v1.0.94
[INFO] [stderr]    Compiling nix v0.11.1
[INFO] [stderr]    Compiling half v1.3.0
[INFO] [stderr]    Compiling serde_cbor v0.9.0
[INFO] [stderr]    Compiling ipc-rs v0.4.2 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> src/lib.rs:10:1
[INFO] [stderr]    |
[INFO] [stderr] 10 | #![feature(associated_type_defaults)]
[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 `ipc-rs`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "0ad7896aab2755324cab50768952fc793ccf489daa050a8fe2b401684839cc14"`
[INFO] running `"docker" "rm" "-f" "0ad7896aab2755324cab50768952fc793ccf489daa050a8fe2b401684839cc14"`
[INFO] [stdout] 0ad7896aab2755324cab50768952fc793ccf489daa050a8fe2b401684839cc14