[INFO] updating cached repository https://github.com/tuzz/supermutation
[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] eafbd87c5cb2e3c1926035910f6f21323a976f03
[INFO] testing tuzz/supermutation against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftuzz%2Fsupermutation" "work/builds/worker-4/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tuzz/supermutation 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/tuzz/supermutation
[INFO] finished tweaking git repo https://github.com/tuzz/supermutation
[INFO] tweaked toml for git repo https://github.com/tuzz/supermutation written to work/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/tuzz/supermutation 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-4/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-4/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] bc3e5ce5ca63c6fbc122909c14e1043264e6f12f7c61bd96eb291c615bab5c81
[INFO] running `"docker" "start" "-a" "bc3e5ce5ca63c6fbc122909c14e1043264e6f12f7c61bd96eb291c615bab5c81"`
[INFO] [stderr]    Compiling regex v1.0.6
[INFO] [stderr]    Compiling bindgen v0.37.4
[INFO] [stderr]    Compiling termcolor v1.0.4
[INFO] [stderr]    Compiling bucket_queue v2.0.0
[INFO] [stderr]    Compiling lehmer v3.0.0
[INFO] [stderr]    Compiling clang-sys v0.23.0
[INFO] [stderr]    Compiling regex-syntax v0.6.3
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]    Compiling which v1.0.5
[INFO] [stderr]    Compiling nom v3.2.1
[INFO] [stderr]    Compiling clap v2.32.0
[INFO] [stderr]    Compiling aho-corasick v0.6.9
[INFO] [stderr]    Compiling cexpr v0.2.3
[INFO] [stderr]    Compiling env_logger v0.5.13
[INFO] [stderr]    Compiling croaring-sys v0.3.7
[INFO] [stderr]    Compiling croaring v0.3.7
[INFO] [stderr]    Compiling supermutation 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(uniform_paths)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(drain_filter)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `supermutation`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "bc3e5ce5ca63c6fbc122909c14e1043264e6f12f7c61bd96eb291c615bab5c81"`
[INFO] running `"docker" "rm" "-f" "bc3e5ce5ca63c6fbc122909c14e1043264e6f12f7c61bd96eb291c615bab5c81"`
[INFO] [stdout] bc3e5ce5ca63c6fbc122909c14e1043264e6f12f7c61bd96eb291c615bab5c81