[INFO] crate futures-timer 0.2.1 is already in cache
[INFO] extracting crate futures-timer 0.2.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/futures-timer/0.2.1
[INFO] extracting crate futures-timer 0.2.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/futures-timer/0.2.1
[INFO] validating manifest of futures-timer-0.2.1 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 futures-timer-0.2.1 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 futures-timer-0.2.1
[INFO] finished frobbing futures-timer-0.2.1
[INFO] frobbed toml for futures-timer-0.2.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/futures-timer/0.2.1/Cargo.toml
[INFO] started frobbing futures-timer-0.2.1
[INFO] finished frobbing futures-timer-0.2.1
[INFO] frobbed toml for futures-timer-0.2.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/futures-timer/0.2.1/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 futures-timer-0.2.1 against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/futures-timer/0.2.1:/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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] a7b0f50ea703e54ab05b7fb665694bcc200dbbdf5d87ba867146525fca453699
[INFO] running `"docker" "start" "-a" "a7b0f50ea703e54ab05b7fb665694bcc200dbbdf5d87ba867146525fca453699"`
[INFO] [stderr]    Compiling futures-timer v0.2.1 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.16s
[INFO] running `"docker" "inspect" "a7b0f50ea703e54ab05b7fb665694bcc200dbbdf5d87ba867146525fca453699"`
[INFO] running `"docker" "rm" "-f" "a7b0f50ea703e54ab05b7fb665694bcc200dbbdf5d87ba867146525fca453699"`
[INFO] [stdout] a7b0f50ea703e54ab05b7fb665694bcc200dbbdf5d87ba867146525fca453699
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/futures-timer/0.2.1:/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" "+1.36.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] c277f24dad7016326d00f4e0d8e3187fbc20d37a8899e800261bee75dd5e08b5
[INFO] running `"docker" "start" "-a" "c277f24dad7016326d00f4e0d8e3187fbc20d37a8899e800261bee75dd5e08b5"`
[INFO] [stderr]    Compiling async-datagram v2.2.0
[INFO] [stderr]    Compiling runtime-attributes v0.3.0-alpha.5
[INFO] [stderr]    Compiling runtime-raw v0.3.0-alpha.4
[INFO] [stderr]    Compiling romio v0.3.0-alpha.9
[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/async-datagram-2.2.0/src/lib.rs:43:1
[INFO] [stderr]    |
[INFO] [stderr] 43 | #![feature(futures_api)]
[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 `async-datagram`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[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/runtime-attributes-0.3.0-alpha.5/src/lib.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![feature(async_await)]
[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/runtime-raw-0.3.0-alpha.4/src/lib.rs:8:1
[INFO] [stderr]   |
[INFO] [stderr] 8 | #![feature(async_await)]
[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 `runtime-attributes`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[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 `runtime-raw`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "c277f24dad7016326d00f4e0d8e3187fbc20d37a8899e800261bee75dd5e08b5"`
[INFO] running `"docker" "rm" "-f" "c277f24dad7016326d00f4e0d8e3187fbc20d37a8899e800261bee75dd5e08b5"`
[INFO] [stdout] c277f24dad7016326d00f4e0d8e3187fbc20d37a8899e800261bee75dd5e08b5