[INFO] fetching crate sharpen 0.0.1...
[INFO] extracting crate sharpen 0.0.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/sharpen/0.0.1
[INFO] extracting crate sharpen 0.0.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/sharpen/0.0.1
[INFO] validating manifest of sharpen-0.0.1 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 sharpen-0.0.1 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 sharpen-0.0.1
[INFO] finished frobbing sharpen-0.0.1
[INFO] frobbed toml for sharpen-0.0.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/sharpen/0.0.1/Cargo.toml
[INFO] started frobbing sharpen-0.0.1
[INFO] finished frobbing sharpen-0.0.1
[INFO] frobbed toml for sharpen-0.0.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/sharpen/0.0.1/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] [stderr]     Blocking waiting for file lock on package cache
[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 sharpen-0.0.1 against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/sharpen/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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] bf8f58a60e089bd3d6664d3a5bdb682f39aab370d04365c5a0a9714c8f58e5f0
[INFO] running `"docker" "start" "-a" "bf8f58a60e089bd3d6664d3a5bdb682f39aab370d04365c5a0a9714c8f58e5f0"`
[INFO] [stderr]    Compiling sharpen v0.0.1 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `"docker" "inspect" "bf8f58a60e089bd3d6664d3a5bdb682f39aab370d04365c5a0a9714c8f58e5f0"`
[INFO] running `"docker" "rm" "-f" "bf8f58a60e089bd3d6664d3a5bdb682f39aab370d04365c5a0a9714c8f58e5f0"`
[INFO] [stdout] bf8f58a60e089bd3d6664d3a5bdb682f39aab370d04365c5a0a9714c8f58e5f0
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/sharpen/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" "+1.36.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] 0b5ea9bf2bb0dbd72ca4ae04df774a5c42386ba616626c97ca6af1d3f1b24f61
[INFO] running `"docker" "start" "-a" "0b5ea9bf2bb0dbd72ca4ae04df774a5c42386ba616626c97ca6af1d3f1b24f61"`
[INFO] [stderr]    Compiling sharpen 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: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 `sharpen`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0b5ea9bf2bb0dbd72ca4ae04df774a5c42386ba616626c97ca6af1d3f1b24f61"`
[INFO] running `"docker" "rm" "-f" "0b5ea9bf2bb0dbd72ca4ae04df774a5c42386ba616626c97ca6af1d3f1b24f61"`
[INFO] [stdout] 0b5ea9bf2bb0dbd72ca4ae04df774a5c42386ba616626c97ca6af1d3f1b24f61