[INFO] crate greenwasm 0.3.1 is already in cache
[INFO] extracting crate greenwasm 0.3.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/greenwasm/0.3.1
[INFO] extracting crate greenwasm 0.3.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/greenwasm/0.3.1
[INFO] validating manifest of greenwasm-0.3.1 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 greenwasm-0.3.1 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 greenwasm-0.3.1
[INFO] finished frobbing greenwasm-0.3.1
[INFO] frobbed toml for greenwasm-0.3.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/greenwasm/0.3.1/Cargo.toml
[INFO] started frobbing greenwasm-0.3.1
[INFO] finished frobbing greenwasm-0.3.1
[INFO] frobbed toml for greenwasm-0.3.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/greenwasm/0.3.1/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 greenwasm-0.3.1 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-3/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/greenwasm/0.3.1:/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] 5bab5e663af89d7f209e7aeac9583061cd5e709c91feddd29c550a02843a7860
[INFO] running `"docker" "start" "-a" "5bab5e663af89d7f209e7aeac9583061cd5e709c91feddd29c550a02843a7860"`
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling libc v0.2.60
[INFO] [stderr]    Compiling rustc-serialize v0.3.24
[INFO] [stderr]    Compiling term v0.4.6
[INFO] [stderr]    Compiling unicode-xid v0.0.4
[INFO] [stderr]    Compiling bitflags v0.8.2
[INFO] [stderr]    Compiling libloading v0.4.3
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling bitflags v0.9.1
[INFO] [stderr]    Compiling peeking_take_while v0.1.2
[INFO] [stderr]    Compiling lazy_static v0.2.11
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[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/smallvec-0.6.10/lib.rs:33:32
[INFO] [stderr]    |
[INFO] [stderr] 33 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stderr]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]    Compiling clang-sys v0.19.0
[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 `smallvec`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "5bab5e663af89d7f209e7aeac9583061cd5e709c91feddd29c550a02843a7860"`
[INFO] running `"docker" "rm" "-f" "5bab5e663af89d7f209e7aeac9583061cd5e709c91feddd29c550a02843a7860"`
[INFO] [stdout] 5bab5e663af89d7f209e7aeac9583061cd5e709c91feddd29c550a02843a7860