[INFO] crate nature_db 0.0.1 is already in cache
[INFO] extracting crate nature_db 0.0.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/nature_db/0.0.1
[INFO] extracting crate nature_db 0.0.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/nature_db/0.0.1
[INFO] validating manifest of nature_db-0.0.1 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 nature_db-0.0.1 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 nature_db-0.0.1
[INFO] finished frobbing nature_db-0.0.1
[INFO] frobbed toml for nature_db-0.0.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/nature_db/0.0.1/Cargo.toml
[INFO] started frobbing nature_db-0.0.1
[INFO] finished frobbing nature_db-0.0.1
[INFO] frobbed toml for nature_db-0.0.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/nature_db/0.0.1/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing nature_db-0.0.1 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-4/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/nature_db/0.0.1:/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] 76b6fd3da4362dd4bb1542d988777def13f4f0c43be910ff001a56d106da07a1
[INFO] running `"docker" "start" "-a" "76b6fd3da4362dd4bb1542d988777def13f4f0c43be910ff001a56d106da07a1"`
[INFO] [stderr]    Compiling mysqlclient-sys v0.2.4
[INFO] [stderr]    Compiling parking_lot_core v0.5.0
[INFO] [stderr]    Compiling actix_derive v0.3.2
[INFO] [stderr]    Compiling uuid v0.7.4
[INFO] [stderr]    Compiling diesel_derives v1.4.0
[INFO] [stderr]    Compiling tokio-signal v0.2.7
[INFO] [stderr]    Compiling trust-dns-proto v0.6.3
[INFO] [stderr]    Compiling trust-dns-proto v0.5.0
[INFO] [stderr]    Compiling parking_lot v0.8.0
[INFO] [stderr]    Compiling r2d2 v0.8.5
[INFO] [stderr]    Compiling trust-dns-resolver v0.10.3
[INFO] [stderr]    Compiling diesel v1.4.2
[INFO] [stderr]    Compiling actix v0.7.9
[INFO] [stderr]    Compiling nature_common v0.0.1
[INFO] [stderr]    Compiling r2d2-diesel v1.0.0
[INFO] [stderr]    Compiling nature_db v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(custom_attribute)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(rustc_private)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `nature_db`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "76b6fd3da4362dd4bb1542d988777def13f4f0c43be910ff001a56d106da07a1"`
[INFO] running `"docker" "rm" "-f" "76b6fd3da4362dd4bb1542d988777def13f4f0c43be910ff001a56d106da07a1"`
[INFO] [stdout] 76b6fd3da4362dd4bb1542d988777def13f4f0c43be910ff001a56d106da07a1