[INFO] crate shannon-entropy 0.2.0 is already in cache
[INFO] extracting crate shannon-entropy 0.2.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/shannon-entropy/0.2.0
[INFO] extracting crate shannon-entropy 0.2.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/shannon-entropy/0.2.0
[INFO] validating manifest of shannon-entropy-0.2.0 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 shannon-entropy-0.2.0 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 shannon-entropy-0.2.0
[INFO] finished frobbing shannon-entropy-0.2.0
[INFO] frobbed toml for shannon-entropy-0.2.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/shannon-entropy/0.2.0/Cargo.toml
[INFO] started frobbing shannon-entropy-0.2.0
[INFO] finished frobbing shannon-entropy-0.2.0
[INFO] frobbed toml for shannon-entropy-0.2.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/shannon-entropy/0.2.0/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] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing shannon-entropy-0.2.0 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-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/shannon-entropy/0.2.0:/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] 88d012ba3514d4894af7604ee3b6e95a6cc60fd198fd2f93e8ae2796193bcf54
[INFO] running `"docker" "start" "-a" "88d012ba3514d4894af7604ee3b6e95a6cc60fd198fd2f93e8ae2796193bcf54"`
[INFO] [stderr]    Compiling shannon-entropy v0.2.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated item 'std::ascii::AsciiExt': use inherent methods instead
[INFO] [stderr]  --> src/lib.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::ascii::AsciiExt;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(deprecated)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::ascii::AsciiExt`
[INFO] [stderr]  --> src/lib.rs:3:5
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::ascii::AsciiExt;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[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 `shannon-entropy`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "88d012ba3514d4894af7604ee3b6e95a6cc60fd198fd2f93e8ae2796193bcf54"`
[INFO] running `"docker" "rm" "-f" "88d012ba3514d4894af7604ee3b6e95a6cc60fd198fd2f93e8ae2796193bcf54"`
[INFO] [stdout] 88d012ba3514d4894af7604ee3b6e95a6cc60fd198fd2f93e8ae2796193bcf54