[INFO] crate kg-diag 0.2.2 is already in cache
[INFO] extracting crate kg-diag 0.2.2 into work/ex/beta-1.38-1/sources/1.37.0/reg/kg-diag/0.2.2
[INFO] extracting crate kg-diag 0.2.2 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/kg-diag/0.2.2
[INFO] validating manifest of kg-diag-0.2.2 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 kg-diag-0.2.2 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 kg-diag-0.2.2
[INFO] finished frobbing kg-diag-0.2.2
[INFO] frobbed toml for kg-diag-0.2.2 written to work/ex/beta-1.38-1/sources/1.37.0/reg/kg-diag/0.2.2/Cargo.toml
[INFO] started frobbing kg-diag-0.2.2
[INFO] finished frobbing kg-diag-0.2.2
[INFO] frobbed toml for kg-diag-0.2.2 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/kg-diag/0.2.2/Cargo.toml
[INFO] crate kg-diag-0.2.2 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 kg-diag-0.2.2 against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/kg-diag/0.2.2:/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] 3061e48d07f8ccef506288f0f03585f7d151e5e1c907d9aea643dcfa16bef7fb
[INFO] running `"docker" "start" "-a" "3061e48d07f8ccef506288f0f03585f7d151e5e1c907d9aea643dcfa16bef7fb"`
[INFO] [stderr]    Compiling syn v0.15.42
[INFO] [stderr]    Compiling ryu v0.2.8
[INFO] [stderr]    Compiling nom v5.0.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]    Compiling lexical-core v0.4.2
[INFO] [stderr]    Compiling kg-utils v0.2.4
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/kg-utils-0.2.4/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(allocator_api, alloc_layout_extra, test)]
[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 `kg-utils`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "3061e48d07f8ccef506288f0f03585f7d151e5e1c907d9aea643dcfa16bef7fb"`
[INFO] running `"docker" "rm" "-f" "3061e48d07f8ccef506288f0f03585f7d151e5e1c907d9aea643dcfa16bef7fb"`
[INFO] [stdout] 3061e48d07f8ccef506288f0f03585f7d151e5e1c907d9aea643dcfa16bef7fb