[INFO] updating cached repository withoutboats/bpb
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/withoutboats/bpb
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/withoutboats/bpb" "work/ex/beta-1.38-1/sources/1.37.0/gh/withoutboats/bpb"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/withoutboats/bpb'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/withoutboats/bpb" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/withoutboats/bpb"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/withoutboats/bpb'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b1ef5ca1d2dea0e2ec0b1616f087f110ea17adfa
[INFO] sha for GitHub repo withoutboats/bpb: b1ef5ca1d2dea0e2ec0b1616f087f110ea17adfa
[INFO] validating manifest of withoutboats/bpb 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 withoutboats/bpb 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 withoutboats/bpb
[INFO] finished frobbing withoutboats/bpb
[INFO] frobbed toml for withoutboats/bpb written to work/ex/beta-1.38-1/sources/1.37.0/gh/withoutboats/bpb/Cargo.toml
[INFO] started frobbing withoutboats/bpb
[INFO] finished frobbing withoutboats/bpb
[INFO] frobbed toml for withoutboats/bpb written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/withoutboats/bpb/Cargo.toml
[INFO] crate withoutboats/bpb already has a lockfile, it will not be regenerated
[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 withoutboats/bpb 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-7/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/withoutboats/bpb:/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] ac5f969d1eaaf1727dd34f1c4f638ab7f02e8e84ff3524d6e4048b4322750cdc
[INFO] running `"docker" "start" "-a" "ac5f969d1eaaf1727dd34f1c4f638ab7f02e8e84ff3524d6e4048b4322750cdc"`
[INFO] [stderr] warning: the cargo feature `edition` is now stable and is no longer necessary to be listed in the manifest
[INFO] [stderr] warning: the cargo feature `rename-dependency` is now stable and is no longer necessary to be listed in the manifest
[INFO] [stderr]    Compiling cc v1.0.18
[INFO] [stderr]    Compiling rand_core v0.2.1
[INFO] [stderr]    Compiling subtle v0.6.3
[INFO] [stderr]    Compiling serde v1.0.70
[INFO] [stderr]    Compiling arrayref v0.3.4
[INFO] [stderr]    Compiling generic-array v0.9.0
[INFO] [stderr]    Compiling synstructure v0.6.1
[INFO] [stderr]    Compiling syn v0.14.4
[INFO] [stderr]    Compiling block-buffer v0.3.3
[INFO] [stderr]    Compiling rand v0.5.4
[INFO] [stderr]    Compiling digest v0.7.5
[INFO] [stderr]    Compiling sha2 v0.7.1
[INFO] [stderr]    Compiling failure_derive v0.1.1
[INFO] [stderr]    Compiling clear_on_drop v0.2.3
[INFO] [stderr]    Compiling backtrace-sys v0.1.23
[INFO] [stderr]    Compiling backtrace v0.3.9
[INFO] [stderr]    Compiling curve25519-dalek v0.18.0
[INFO] [stderr]    Compiling failure v0.1.1
[INFO] [stderr]    Compiling serde_derive v1.0.70
[INFO] [stderr]    Compiling ed25519-dalek v0.7.0
[INFO] [stderr]    Compiling pbp v0.4.0
[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/pbp-0.4.0/src/lib.rs:10:1
[INFO] [stderr]    |
[INFO] [stderr] 10 | #![feature(rust_2018_preview)]
[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 `pbp`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "ac5f969d1eaaf1727dd34f1c4f638ab7f02e8e84ff3524d6e4048b4322750cdc"`
[INFO] running `"docker" "rm" "-f" "ac5f969d1eaaf1727dd34f1c4f638ab7f02e8e84ff3524d6e4048b4322750cdc"`
[INFO] [stdout] ac5f969d1eaaf1727dd34f1c4f638ab7f02e8e84ff3524d6e4048b4322750cdc