[INFO] updating cached repository emk/drop-async-examples
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/emk/drop-async-examples
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/emk/drop-async-examples" "work/ex/beta-1.38-1/sources/1.37.0/gh/emk/drop-async-examples"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/emk/drop-async-examples'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/emk/drop-async-examples" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/emk/drop-async-examples"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/emk/drop-async-examples'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 48d2b3609ae85fbba497b5134135ded3fbedbb32
[INFO] sha for GitHub repo emk/drop-async-examples: 48d2b3609ae85fbba497b5134135ded3fbedbb32
[INFO] validating manifest of emk/drop-async-examples 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 emk/drop-async-examples 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 emk/drop-async-examples
[INFO] finished frobbing emk/drop-async-examples
[INFO] frobbed toml for emk/drop-async-examples written to work/ex/beta-1.38-1/sources/1.37.0/gh/emk/drop-async-examples/Cargo.toml
[INFO] started frobbing emk/drop-async-examples
[INFO] finished frobbing emk/drop-async-examples
[INFO] frobbed toml for emk/drop-async-examples written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/emk/drop-async-examples/Cargo.toml
[INFO] crate emk/drop-async-examples 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 emk/drop-async-examples against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-7/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/emk/drop-async-examples:/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-2019-08-13" "build" "--frozen"`
[INFO] [stdout] c29416181c586f59b55b467d95fa2fb4f6485a253c6f364f8b5a4f77a56c9452
[INFO] running `"docker" "start" "-a" "c29416181c586f59b55b467d95fa2fb4f6485a253c6f364f8b5a4f77a56c9452"`
[INFO] [stderr]    Compiling cc v1.0.30
[INFO] [stderr]    Compiling futures v0.1.25
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling syn v0.15.28
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/futures-0.1.25/src/lib.rs:161:34
[INFO] [stderr]     |
[INFO] [stderr] 161 | #![cfg_attr(feature = "nightly", feature(pin))]
[INFO] [stderr]     |                                  ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling mio v0.6.16
[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 `futures`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "c29416181c586f59b55b467d95fa2fb4f6485a253c6f364f8b5a4f77a56c9452"`
[INFO] running `"docker" "rm" "-f" "c29416181c586f59b55b467d95fa2fb4f6485a253c6f364f8b5a4f77a56c9452"`
[INFO] [stdout] c29416181c586f59b55b467d95fa2fb4f6485a253c6f364f8b5a4f77a56c9452