[INFO] updating cached repository https://github.com/iterate/miniwoop-backend
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 4e6bc456029694b3624ddb52a303126a58c68449
[INFO] testing iterate/miniwoop-backend against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiterate%2Fminiwoop-backend" "work/builds/worker-0/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/iterate/miniwoop-backend on toolchain beta-2019-09-28
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/iterate/miniwoop-backend
[INFO] finished tweaking git repo https://github.com/iterate/miniwoop-backend
[INFO] tweaked toml for git repo https://github.com/iterate/miniwoop-backend written to work/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/iterate/miniwoop-backend already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-0/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2019-09-28" "build" "--frozen"`
[INFO] [stdout] bf200d257f52dd100caa430eb2f0ac9771acc3e5e44b0493cf6a19057d30bf7a
[INFO] running `"docker" "start" "-a" "bf200d257f52dd100caa430eb2f0ac9771acc3e5e44b0493cf6a19057d30bf7a"`
[INFO] [stderr]    Compiling cfg-if v0.1.1
[INFO] [stderr]    Compiling iovec v0.1.0
[INFO] [stderr]    Compiling thread-id v3.1.0
[INFO] [stderr]    Compiling memchr v1.0.1
[INFO] [stderr]    Compiling num_cpus v1.5.1
[INFO] [stderr]    Compiling tokio-service v0.1.0
[INFO] [stderr]    Compiling base64 v0.6.0
[INFO] [stderr]    Compiling uuid v0.5.0
[INFO] [stderr]    Compiling serde_json v1.0.2
[INFO] [stderr]    Compiling serde_derive_internals v0.15.1
[INFO] [stderr]    Compiling chrono v0.3.1
[INFO] [stderr]    Compiling mime v0.3.2
[INFO] [stderr]    Compiling net2 v0.2.29
[INFO] [stderr]    Compiling thread_local v0.3.3
[INFO] [stderr]    Compiling bytes v0.4.4
[INFO] [stderr]    Compiling aho-corasick v0.6.3
[INFO] [stderr]    Compiling futures-cpupool v0.1.5
[INFO] [stderr]    Compiling mio v0.6.9
[INFO] [stderr]    Compiling regex v0.2.2
[INFO] [stderr]    Compiling tokio-io v0.1.2
[INFO] [stderr]    Compiling serde_derive v1.0.8
[INFO] [stderr]    Compiling tokio-core v0.1.8
[INFO] [stderr]    Compiling env_logger v0.4.3
[INFO] [stderr]    Compiling tokio-proto v0.1.1
[INFO] [stderr]    Compiling pretty_env_logger v0.1.1
[INFO] [stderr]    Compiling hyper v0.11.0
[INFO] [stderr]    Compiling miniwoop-backend v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(slice_patterns)]
[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 `miniwoop-backend`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "bf200d257f52dd100caa430eb2f0ac9771acc3e5e44b0493cf6a19057d30bf7a"`
[INFO] running `"docker" "rm" "-f" "bf200d257f52dd100caa430eb2f0ac9771acc3e5e44b0493cf6a19057d30bf7a"`
[INFO] [stdout] bf200d257f52dd100caa430eb2f0ac9771acc3e5e44b0493cf6a19057d30bf7a