[INFO] crate fs2 0.4.3 is already in cache
[INFO] extracting crate fs2 0.4.3 into work/ex/beta-1.37-6/sources/1.36.0/reg/fs2/0.4.3
[INFO] extracting crate fs2 0.4.3 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/fs2/0.4.3
[INFO] validating manifest of fs2-0.4.3 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 fs2-0.4.3 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 fs2-0.4.3
[INFO] finished frobbing fs2-0.4.3
[INFO] frobbed toml for fs2-0.4.3 written to work/ex/beta-1.37-6/sources/1.36.0/reg/fs2/0.4.3/Cargo.toml
[INFO] started frobbing fs2-0.4.3
[INFO] finished frobbing fs2-0.4.3
[INFO] frobbed toml for fs2-0.4.3 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/fs2/0.4.3/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] [stderr]     Blocking waiting for file lock on package cache lock
[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 fs2-0.4.3 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-2/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/fs2/0.4.3:/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] b19ed8dba40bb33ac48e81828f161d14ccb8ceb4d85d7ea1a3ba766895f4a69d
[INFO] running `"docker" "start" "-a" "b19ed8dba40bb33ac48e81828f161d14ccb8ceb4d85d7ea1a3ba766895f4a69d"`
[INFO] [stderr]    Compiling fs2 v0.4.3 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `"docker" "inspect" "b19ed8dba40bb33ac48e81828f161d14ccb8ceb4d85d7ea1a3ba766895f4a69d"`
[INFO] running `"docker" "rm" "-f" "b19ed8dba40bb33ac48e81828f161d14ccb8ceb4d85d7ea1a3ba766895f4a69d"`
[INFO] [stdout] b19ed8dba40bb33ac48e81828f161d14ccb8ceb4d85d7ea1a3ba766895f4a69d
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-2/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/fs2/0.4.3:/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] b302bda62e724361bbb51a2abafc4e46e1619673c8f8c0565054f1cc99a6e9bd
[INFO] running `"docker" "start" "-a" "b302bda62e724361bbb51a2abafc4e46e1619673c8f8c0565054f1cc99a6e9bd"`
[INFO] [stderr]    Compiling fs2 v0.4.3 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:5:19
[INFO] [stderr]   |
[INFO] [stderr] 5 | #![cfg_attr(test, feature(test))]
[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 `fs2`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "b302bda62e724361bbb51a2abafc4e46e1619673c8f8c0565054f1cc99a6e9bd"`
[INFO] running `"docker" "rm" "-f" "b302bda62e724361bbb51a2abafc4e46e1619673c8f8c0565054f1cc99a6e9bd"`
[INFO] [stdout] b302bda62e724361bbb51a2abafc4e46e1619673c8f8c0565054f1cc99a6e9bd