[INFO] crate mutagen-plugin 0.1.2 is already in cache
[INFO] extracting crate mutagen-plugin 0.1.2 into work/ex/beta-1.37-6/sources/1.36.0/reg/mutagen-plugin/0.1.2
[INFO] extracting crate mutagen-plugin 0.1.2 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/mutagen-plugin/0.1.2
[INFO] validating manifest of mutagen-plugin-0.1.2 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of mutagen-plugin-0.1.2 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing mutagen-plugin-0.1.2
[INFO] finished frobbing mutagen-plugin-0.1.2
[INFO] frobbed toml for mutagen-plugin-0.1.2 written to work/ex/beta-1.37-6/sources/1.36.0/reg/mutagen-plugin/0.1.2/Cargo.toml
[INFO] started frobbing mutagen-plugin-0.1.2
[INFO] finished frobbing mutagen-plugin-0.1.2
[INFO] frobbed toml for mutagen-plugin-0.1.2 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/mutagen-plugin/0.1.2/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing mutagen-plugin-0.1.2 against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/mutagen-plugin/0.1.2:/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-2019-07-23" "build" "--frozen"`
[INFO] [stdout] 9876c910b0ea131824fbf34c5bbf760a68b3867ff3936c857e06b15afc42e588
[INFO] running `"docker" "start" "-a" "9876c910b0ea131824fbf34c5bbf760a68b3867ff3936c857e06b15afc42e588"`
[INFO] [stderr]    Compiling mutagen v0.1.2
[INFO] [stderr]    Compiling mutagen-plugin v0.1.2 (/opt/crater/workdir)
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> build.rs:15:30
[INFO] [stderr]    |
[INFO] [stderr] 15 | fn write_binop_arm(out: &mut Write,
[INFO] [stderr]    |                              ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(bare_trait_objects)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> build.rs:59:33
[INFO] [stderr]    |
[INFO] [stderr] 59 | fn write_opassign_arm(out: &mut Write,
[INFO] [stderr]    |                                 ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[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/mutagen-0.1.2/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(specialization, atomic_min_max, try_from, assoc_unix_epoch)]
[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 `mutagen`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "9876c910b0ea131824fbf34c5bbf760a68b3867ff3936c857e06b15afc42e588"`
[INFO] running `"docker" "rm" "-f" "9876c910b0ea131824fbf34c5bbf760a68b3867ff3936c857e06b15afc42e588"`
[INFO] [stdout] 9876c910b0ea131824fbf34c5bbf760a68b3867ff3936c857e06b15afc42e588