[INFO] updating cached repository urugang/create-lang-with-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/urugang/create-lang-with-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/urugang/create-lang-with-rust" "work/ex/beta-1.38-1/sources/1.37.0/gh/urugang/create-lang-with-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/urugang/create-lang-with-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/urugang/create-lang-with-rust" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/urugang/create-lang-with-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/urugang/create-lang-with-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1443b2f41183f242324d59b1e2a8827acf6bbfdd
[INFO] sha for GitHub repo urugang/create-lang-with-rust: 1443b2f41183f242324d59b1e2a8827acf6bbfdd
[INFO] validating manifest of urugang/create-lang-with-rust 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 urugang/create-lang-with-rust 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 urugang/create-lang-with-rust
[INFO] finished frobbing urugang/create-lang-with-rust
[INFO] frobbed toml for urugang/create-lang-with-rust written to work/ex/beta-1.38-1/sources/1.37.0/gh/urugang/create-lang-with-rust/Cargo.toml
[INFO] started frobbing urugang/create-lang-with-rust
[INFO] finished frobbing urugang/create-lang-with-rust
[INFO] frobbed toml for urugang/create-lang-with-rust written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/urugang/create-lang-with-rust/Cargo.toml
[INFO] crate urugang/create-lang-with-rust 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 urugang/create-lang-with-rust 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-5/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/urugang/create-lang-with-rust:/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] accc2632a6670f36690292059b26612f7229766a5c3b3dc7af4bbdb900044e16
[INFO] running `"docker" "start" "-a" "accc2632a6670f36690292059b26612f7229766a5c3b3dc7af4bbdb900044e16"`
[INFO] [stderr]    Compiling pest_generator v2.1.0
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]    Compiling meetup-2019-02 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![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 `meetup-2019-02`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "accc2632a6670f36690292059b26612f7229766a5c3b3dc7af4bbdb900044e16"`
[INFO] running `"docker" "rm" "-f" "accc2632a6670f36690292059b26612f7229766a5c3b3dc7af4bbdb900044e16"`
[INFO] [stdout] accc2632a6670f36690292059b26612f7229766a5c3b3dc7af4bbdb900044e16