[INFO] crate rustfmt-core 0.4.0 is already in cache
[INFO] extracting crate rustfmt-core 0.4.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/rustfmt-core/0.4.0
[INFO] extracting crate rustfmt-core 0.4.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustfmt-core/0.4.0
[INFO] validating manifest of rustfmt-core-0.4.0 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 rustfmt-core-0.4.0 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 rustfmt-core-0.4.0
[INFO] finished frobbing rustfmt-core-0.4.0
[INFO] frobbed toml for rustfmt-core-0.4.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/rustfmt-core/0.4.0/Cargo.toml
[INFO] started frobbing rustfmt-core-0.4.0
[INFO] finished frobbing rustfmt-core-0.4.0
[INFO] frobbed toml for rustfmt-core-0.4.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rustfmt-core/0.4.0/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 rustfmt-core-0.4.0 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-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/rustfmt-core/0.4.0:/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] b2f06ad6093e3fb2acacb35a14265aa690d3271ff90b5fb68874d859e233255a
[INFO] running `"docker" "start" "-a" "b2f06ad6093e3fb2acacb35a14265aa690d3271ff90b5fb68874d859e233255a"`
[INFO] [stderr]    Compiling rustc-ap-serialize v29.0.0
[INFO] [stderr]    Compiling rustc-ap-syntax v29.0.0
[INFO] [stderr]    Compiling owning_ref v0.3.3
[INFO] [stderr]    Compiling rustc-ap-rustc_cratesio_shim v29.0.0
[INFO] [stderr]    Compiling toml v0.4.10
[INFO] [stderr]    Compiling parking_lot_core v0.2.14
[INFO] [stderr]    Compiling derive-new v0.5.8
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-ap-serialize-29.0.0/lib.rs:24:1
[INFO] [stderr]    |
[INFO] [stderr] 24 | #![feature(rustc_private, box_syntax)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/parking_lot_core-0.2.14/src/lib.rs:41:60
[INFO] [stderr]    |
[INFO] [stderr] 41 | #![cfg_attr(all(feature = "nightly", target_os = "linux"), feature(integer_atomics))]
[INFO] [stderr]    |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-ap-serialize-29.0.0/lib.rs:25:1
[INFO] [stderr]    |
[INFO] [stderr] 25 | #![feature(core_intrinsics)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-ap-serialize-29.0.0/lib.rs:26:1
[INFO] [stderr]    |
[INFO] [stderr] 26 | #![feature(i128_type)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-ap-serialize-29.0.0/lib.rs:27:1
[INFO] [stderr]    |
[INFO] [stderr] 27 | #![feature(specialization)]
[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 `parking_lot_core`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rustc-ap-serialize`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "b2f06ad6093e3fb2acacb35a14265aa690d3271ff90b5fb68874d859e233255a"`
[INFO] running `"docker" "rm" "-f" "b2f06ad6093e3fb2acacb35a14265aa690d3271ff90b5fb68874d859e233255a"`
[INFO] [stdout] b2f06ad6093e3fb2acacb35a14265aa690d3271ff90b5fb68874d859e233255a