[INFO] crate microcrates-bytes 0.4.8 is already in cache
[INFO] extracting crate microcrates-bytes 0.4.8 into work/ex/beta-1.38-1/sources/1.37.0/reg/microcrates-bytes/0.4.8
[INFO] extracting crate microcrates-bytes 0.4.8 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/microcrates-bytes/0.4.8
[INFO] validating manifest of microcrates-bytes-0.4.8 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 microcrates-bytes-0.4.8 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 microcrates-bytes-0.4.8
[INFO] finished frobbing microcrates-bytes-0.4.8
[INFO] frobbed toml for microcrates-bytes-0.4.8 written to work/ex/beta-1.38-1/sources/1.37.0/reg/microcrates-bytes/0.4.8/Cargo.toml
[INFO] started frobbing microcrates-bytes-0.4.8
[INFO] finished frobbing microcrates-bytes-0.4.8
[INFO] frobbed toml for microcrates-bytes-0.4.8 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/microcrates-bytes/0.4.8/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 microcrates-bytes-0.4.8 against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-3/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/microcrates-bytes/0.4.8:/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] c094e69e10dc5300dd6e92d01024d5300d07bc3127abd6217c42913413c2e403
[INFO] running `"docker" "start" "-a" "c094e69e10dc5300dd6e92d01024d5300d07bc3127abd6217c42913413c2e403"`
[INFO] [stderr]    Compiling microcrates-bytes v0.4.8 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:74:34
[INFO] [stderr]    |
[INFO] [stderr] 74 | #![cfg_attr(feature = "nightly", feature(alloc, read_initializer, try_from))]
[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 `microcrates-bytes`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "c094e69e10dc5300dd6e92d01024d5300d07bc3127abd6217c42913413c2e403"`
[INFO] running `"docker" "rm" "-f" "c094e69e10dc5300dd6e92d01024d5300d07bc3127abd6217c42913413c2e403"`
[INFO] [stdout] c094e69e10dc5300dd6e92d01024d5300d07bc3127abd6217c42913413c2e403