[INFO] crate oncemutex 0.1.1 is already in cache
[INFO] extracting crate oncemutex 0.1.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/oncemutex/0.1.1
[INFO] extracting crate oncemutex 0.1.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/oncemutex/0.1.1
[INFO] validating manifest of oncemutex-0.1.1 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of oncemutex-0.1.1 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing oncemutex-0.1.1
[INFO] finished frobbing oncemutex-0.1.1
[INFO] frobbed toml for oncemutex-0.1.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/oncemutex/0.1.1/Cargo.toml
[INFO] started frobbing oncemutex-0.1.1
[INFO] finished frobbing oncemutex-0.1.1
[INFO] frobbed toml for oncemutex-0.1.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/oncemutex/0.1.1/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing oncemutex-0.1.1 against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-3/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/oncemutex/0.1.1:/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" "+beta-2019-07-23" "build" "--frozen"`
[INFO] [stdout] 1f091b6dddc277c468ed61c3ddc75e783197b2c183559a7e0e1eca6d95632850
[INFO] running `"docker" "start" "-a" "1f091b6dddc277c468ed61c3ddc75e783197b2c183559a7e0e1eca6d95632850"`
[INFO] [stderr]    Compiling oncemutex v0.1.1 (/opt/crater/workdir)
[INFO] [stderr] warning: unnecessary `unsafe` block
[INFO] [stderr]   --> src/lib.rs:86:9
[INFO] [stderr]    |
[INFO] [stderr] 86 |         unsafe { self.data.into_inner() }
[INFO] [stderr]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stderr]    |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]   --> src/lib.rs:1:23
[INFO] [stderr]    |
[INFO] [stderr] 1  | #![deny(missing_docs, warnings)]
[INFO] [stderr]    |                       ^^^^^^^^
[INFO] [stderr]    = note: #[warn(unused_unsafe)] implied by #[warn(warnings)]
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.21s
[INFO] running `"docker" "inspect" "1f091b6dddc277c468ed61c3ddc75e783197b2c183559a7e0e1eca6d95632850"`
[INFO] running `"docker" "rm" "-f" "1f091b6dddc277c468ed61c3ddc75e783197b2c183559a7e0e1eca6d95632850"`
[INFO] [stdout] 1f091b6dddc277c468ed61c3ddc75e783197b2c183559a7e0e1eca6d95632850
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-3/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/oncemutex/0.1.1:/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" "+beta-2019-07-23" "test" "--frozen" "--no-run"`
[INFO] [stdout] 7b5d26b68f9e8fe00d1cb7aeef3bf4721c70dee5f74d7c02176959f6e14db342
[INFO] running `"docker" "start" "-a" "7b5d26b68f9e8fe00d1cb7aeef3bf4721c70dee5f74d7c02176959f6e14db342"`
[INFO] [stderr]    Compiling oncemutex v0.1.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:2:19
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![cfg_attr(test, feature(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 `oncemutex`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "7b5d26b68f9e8fe00d1cb7aeef3bf4721c70dee5f74d7c02176959f6e14db342"`
[INFO] running `"docker" "rm" "-f" "7b5d26b68f9e8fe00d1cb7aeef3bf4721c70dee5f74d7c02176959f6e14db342"`
[INFO] [stdout] 7b5d26b68f9e8fe00d1cb7aeef3bf4721c70dee5f74d7c02176959f6e14db342