[INFO] crate flx 0.2.2 is already in cache
[INFO] extracting crate flx 0.2.2 into work/ex/beta-1.37-6/sources/1.36.0/reg/flx/0.2.2
[INFO] extracting crate flx 0.2.2 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/flx/0.2.2
[INFO] validating manifest of flx-0.2.2 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 flx-0.2.2 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 flx-0.2.2
[INFO] finished frobbing flx-0.2.2
[INFO] frobbed toml for flx-0.2.2 written to work/ex/beta-1.37-6/sources/1.36.0/reg/flx/0.2.2/Cargo.toml
[INFO] started frobbing flx-0.2.2
[INFO] finished frobbing flx-0.2.2
[INFO] frobbed toml for flx-0.2.2 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/flx/0.2.2/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] [stderr]     Blocking waiting for file lock on package cache
[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 flx-0.2.2 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-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/flx/0.2.2:/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] 61fe2b31749703a51007daf8bf5b8b78dea585986b676a474a5e9c5590533cbc
[INFO] running `"docker" "start" "-a" "61fe2b31749703a51007daf8bf5b8b78dea585986b676a474a5e9c5590533cbc"`
[INFO] [stderr]     Blocking waiting for file lock on package cache lock
[INFO] [stderr]    Compiling flx v0.2.2 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.63s
[INFO] running `"docker" "inspect" "61fe2b31749703a51007daf8bf5b8b78dea585986b676a474a5e9c5590533cbc"`
[INFO] running `"docker" "rm" "-f" "61fe2b31749703a51007daf8bf5b8b78dea585986b676a474a5e9c5590533cbc"`
[INFO] [stdout] 61fe2b31749703a51007daf8bf5b8b78dea585986b676a474a5e9c5590533cbc
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/flx/0.2.2:/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] 4132e53fe7d19ea8c35a9c67c437dda39ee8f430091d9e4dbc020b4ae091fc1c
[INFO] running `"docker" "start" "-a" "4132e53fe7d19ea8c35a9c67c437dda39ee8f430091d9e4dbc020b4ae091fc1c"`
[INFO] [stderr]    Compiling flx v0.2.2 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:7:19
[INFO] [stderr]   |
[INFO] [stderr] 7 | #![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 `flx`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "4132e53fe7d19ea8c35a9c67c437dda39ee8f430091d9e4dbc020b4ae091fc1c"`
[INFO] running `"docker" "rm" "-f" "4132e53fe7d19ea8c35a9c67c437dda39ee8f430091d9e4dbc020b4ae091fc1c"`
[INFO] [stdout] 4132e53fe7d19ea8c35a9c67c437dda39ee8f430091d9e4dbc020b4ae091fc1c