[INFO] crate persistentcache 0.1.6 is already in cache
[INFO] extracting crate persistentcache 0.1.6 into work/ex/beta-1.38-1/sources/1.37.0/reg/persistentcache/0.1.6
[INFO] extracting crate persistentcache 0.1.6 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/persistentcache/0.1.6
[INFO] validating manifest of persistentcache-0.1.6 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 persistentcache-0.1.6 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 persistentcache-0.1.6
[INFO] finished frobbing persistentcache-0.1.6
[INFO] frobbed toml for persistentcache-0.1.6 written to work/ex/beta-1.38-1/sources/1.37.0/reg/persistentcache/0.1.6/Cargo.toml
[INFO] started frobbing persistentcache-0.1.6
[INFO] finished frobbing persistentcache-0.1.6
[INFO] frobbed toml for persistentcache-0.1.6 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/persistentcache/0.1.6/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 persistentcache-0.1.6 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-3/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/persistentcache/0.1.6:/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] cbfd10ec65ebd6c684952ec25e687d7821612e1aa16a34c3d0ece253e6802e7d
[INFO] running `"docker" "start" "-a" "cbfd10ec65ebd6c684952ec25e687d7821612e1aa16a34c3d0ece253e6802e7d"`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling sha1 v0.2.0
[INFO] [stderr]    Compiling proc-macro2 v0.1.10
[INFO] [stderr]    Compiling redis v0.8.0
[INFO] [stderr]    Compiling futures-await-quote v0.4.0
[INFO] [stderr]    Compiling futures-await-synom v0.12.0
[INFO] [stderr]    Compiling futures-await-syn v0.12.0
[INFO] [stderr]    Compiling persistentcache_procmacro v0.0.3
[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/persistentcache_procmacro-0.0.3/src/lib.rs:15:1
[INFO] [stderr]    |
[INFO] [stderr] 15 | #![feature(proc_macro)]
[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 `persistentcache_procmacro`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "cbfd10ec65ebd6c684952ec25e687d7821612e1aa16a34c3d0ece253e6802e7d"`
[INFO] running `"docker" "rm" "-f" "cbfd10ec65ebd6c684952ec25e687d7821612e1aa16a34c3d0ece253e6802e7d"`
[INFO] [stdout] cbfd10ec65ebd6c684952ec25e687d7821612e1aa16a34c3d0ece253e6802e7d