[INFO] crate tars-stream 0.1.1 is already in cache
[INFO] extracting crate tars-stream 0.1.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/tars-stream/0.1.1
[INFO] extracting crate tars-stream 0.1.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tars-stream/0.1.1
[INFO] validating manifest of tars-stream-0.1.1 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 tars-stream-0.1.1 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 tars-stream-0.1.1
[INFO] finished frobbing tars-stream-0.1.1
[INFO] frobbed toml for tars-stream-0.1.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/tars-stream/0.1.1/Cargo.toml
[INFO] started frobbing tars-stream-0.1.1
[INFO] finished frobbing tars-stream-0.1.1
[INFO] frobbed toml for tars-stream-0.1.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tars-stream/0.1.1/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing tars-stream-0.1.1 against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-1/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/tars-stream/0.1.1:/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-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 3afef237990149b4efc64b037cb19787e26556d1ac94d3e7cf87dae99c5428aa
[INFO] running `"docker" "start" "-a" "3afef237990149b4efc64b037cb19787e26556d1ac94d3e7cf87dae99c5428aa"`
[INFO] [stderr]    Compiling tars-stream v0.1.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(try_from)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(core_intrinsics)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(extern_prelude)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(specialization)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[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 `tars-stream`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "3afef237990149b4efc64b037cb19787e26556d1ac94d3e7cf87dae99c5428aa"`
[INFO] running `"docker" "rm" "-f" "3afef237990149b4efc64b037cb19787e26556d1ac94d3e7cf87dae99c5428aa"`
[INFO] [stdout] 3afef237990149b4efc64b037cb19787e26556d1ac94d3e7cf87dae99c5428aa