[INFO] updating cached repository https://github.com/busarovalex/mp3-meta
[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] dc2f9188c6fba277153926f265aebfd61e5a7f37
[INFO] testing busarovalex/mp3-meta against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbusarovalex%2Fmp3-meta" "work/builds/worker-11/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/busarovalex/mp3-meta 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/busarovalex/mp3-meta
[INFO] finished tweaking git repo https://github.com/busarovalex/mp3-meta
[INFO] tweaked toml for git repo https://github.com/busarovalex/mp3-meta written to work/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/busarovalex/mp3-meta 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-11/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-11/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] 31cc640d97a8a55b25ae99321082076caf0b61a8a8580c4f5f449407f1b6e87c
[INFO] running `"docker" "start" "-a" "31cc640d97a8a55b25ae99321082076caf0b61a8a8580c4f5f449407f1b6e87c"`
[INFO] [stderr]    Compiling libc v0.2.31
[INFO] [stderr]    Compiling derive_builder v0.4.7
[INFO] [stderr]    Compiling miniz-sys v0.1.10
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling memchr v1.0.1
[INFO] [stderr]    Compiling term_size v0.3.0
[INFO] [stderr]    Compiling atty v0.2.2
[INFO] [stderr]    Compiling textwrap v0.8.0
[INFO] [stderr]    Compiling aho-corasick v0.6.3
[INFO] [stderr]    Compiling flate2 v0.2.20
[INFO] [stderr]    Compiling clap v2.26.2
[INFO] [stderr]    Compiling regex v0.2.2
[INFO] [stderr]    Compiling derive_builder_core v0.1.7
[INFO] [stderr]    Compiling id3 v0.2.1 (https://github.com/jameshurst/rust-id3.git?rev=21ebef8706dd5f2b1bf6b05cc87ded3b20d54dcd#21ebef87)
[INFO] [stderr]    Compiling mp3meta 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(iterator_for_each)]
[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 `mp3meta`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "31cc640d97a8a55b25ae99321082076caf0b61a8a8580c4f5f449407f1b6e87c"`
[INFO] running `"docker" "rm" "-f" "31cc640d97a8a55b25ae99321082076caf0b61a8a8580c4f5f449407f1b6e87c"`
[INFO] [stdout] 31cc640d97a8a55b25ae99321082076caf0b61a8a8580c4f5f449407f1b6e87c