Aug 02 04:12:14.238 INFO checking monotonic_solver-0.2.1 against 1.27.2 for lazy_static-1
Aug 02 04:12:14.238 INFO running: cargo +1.27.2 check --frozen --all --all-targets
Aug 02 04:12:14.238 INFO creating container for: cargo +1.27.2 check --frozen --all --all-targets
Aug 02 04:12:14.238 INFO running `"docker" "create" "-v" "/tmp/crater.75N3FBMnzTtC:/source:ro,Z" "-v" "/home/ec2-user/crater/./work/local/target-dirs/lazy_static-1/worker-4/1.27.2:/target:rw,Z" "-v" "/home/ec2-user/crater/./work/local/cargo-home:/cargo-home:ro,Z" "-v" "/home/ec2-user/crater/./work/local/rustup-home:/rustup-home:ro,Z" "-v" "/home/ec2-user/crater/./work/local/cargo-home/git:/cargo-home/git:rw,Z" "-e" "USER_ID=500" "-e" "CMD=cargo +1.27.2 check --frozen --all --all-targets" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "crater"`
Aug 02 04:12:14.531 INFO blam! 68d919d86139bdc97b7577103437a095b4fa5a1087228b2bddb472f3927344c8
Aug 02 04:12:14.533 INFO running `"docker" "start" "-a" "68d919d86139bdc97b7577103437a095b4fa5a1087228b2bddb472f3927344c8"`
Aug 02 04:12:15.573 INFO kablam!     Checking monotonic_solver v0.2.1 (file:///source)
Aug 02 04:12:17.524 INFO kablam! error[E0554]: #![feature] may not be used on the stable release channel
Aug 02 04:12:17.524 INFO kablam!  --> examples/drama.rs:1:1
Aug 02 04:12:17.525 INFO kablam!   |
Aug 02 04:12:17.525 INFO kablam! 1 | #![feature(box_patterns)]
Aug 02 04:12:17.525 INFO kablam!   | ^^^^^^^^^^^^^^^^^^^^^^^^^
Aug 02 04:12:17.525 INFO kablam! 
Aug 02 04:12:17.527 INFO kablam! error: aborting due to previous error
Aug 02 04:12:17.527 INFO kablam! 
Aug 02 04:12:17.527 INFO kablam! For more information about this error, try `rustc --explain E0554`.
Aug 02 04:12:17.535 INFO kablam! error: Could not compile `monotonic_solver`.
Aug 02 04:12:17.535 INFO kablam! warning: build failed, waiting for other jobs to finish...
Aug 02 04:12:17.642 INFO kablam! error: build failed
Aug 02 04:12:17.643 INFO kablam! su: No module specific data is present
Aug 02 04:12:18.282 INFO running `"docker" "rm" "-f" "68d919d86139bdc97b7577103437a095b4fa5a1087228b2bddb472f3927344c8"`
Aug 02 04:12:18.422 INFO blam! 68d919d86139bdc97b7577103437a095b4fa5a1087228b2bddb472f3927344c8