[INFO] updating cached repository mastfissh/rust-playground
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/mastfissh/rust-playground
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/mastfissh/rust-playground" "work/ex/beta-1.38-1/sources/1.37.0/gh/mastfissh/rust-playground"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/mastfissh/rust-playground'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/mastfissh/rust-playground" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/mastfissh/rust-playground"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/mastfissh/rust-playground'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a68ef69286ea46f25cc9243d5b54d356c7d49416
[INFO] sha for GitHub repo mastfissh/rust-playground: a68ef69286ea46f25cc9243d5b54d356c7d49416
[INFO] validating manifest of mastfissh/rust-playground 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 mastfissh/rust-playground 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 mastfissh/rust-playground
[INFO] finished frobbing mastfissh/rust-playground
[INFO] frobbed toml for mastfissh/rust-playground written to work/ex/beta-1.38-1/sources/1.37.0/gh/mastfissh/rust-playground/Cargo.toml
[INFO] started frobbing mastfissh/rust-playground
[INFO] finished frobbing mastfissh/rust-playground
[INFO] frobbed toml for mastfissh/rust-playground written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/mastfissh/rust-playground/Cargo.toml
[INFO] crate mastfissh/rust-playground 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 mastfissh/rust-playground 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-6/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/mastfissh/rust-playground:/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] dc752ae63673f5203699314d35e72a65c0309098c819230bf6bc2cdc2b048c30
[INFO] running `"docker" "start" "-a" "dc752ae63673f5203699314d35e72a65c0309098c819230bf6bc2cdc2b048c30"`
[INFO] [stderr]    Compiling state v0.2.1
[INFO] [stderr]    Compiling rocket v0.2.6
[INFO] [stderr]    Compiling rocket_codegen v0.2.6
[INFO] [stderr]    Compiling num_cpus v1.4.0
[INFO] [stderr]    Compiling memchr v1.0.1
[INFO] [stderr]    Compiling term-painter v0.2.3
[INFO] [stderr]    Compiling idna v0.1.1
[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/state-0.2.1/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(const_fn)]
[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 `state`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "dc752ae63673f5203699314d35e72a65c0309098c819230bf6bc2cdc2b048c30"`
[INFO] running `"docker" "rm" "-f" "dc752ae63673f5203699314d35e72a65c0309098c819230bf6bc2cdc2b048c30"`
[INFO] [stdout] dc752ae63673f5203699314d35e72a65c0309098c819230bf6bc2cdc2b048c30