Sep 10 20:12:14.887 INFO checking discard-1.0.3 against try#3a2610c2a16575649896925631bf8cec4f4b1961 for pr-54090 Sep 10 20:12:14.887 INFO running: cargo +3a2610c2a16575649896925631bf8cec4f4b1961-alt check --frozen --all --all-targets Sep 10 20:12:14.887 INFO running `"docker" "create" "-v" "/home/ec2-user/crater/./work/local/test-source/worker-6/pr-54090/try#3a2610c2a16575649896925631bf8cec4f4b1961:/source:ro,Z" "-v" "/home/ec2-user/crater/./work/local/target-dirs/pr-54090/worker-6/try#3a2610c2a16575649896925631bf8cec4f4b1961:/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" "-e" "USER_ID=1000" "-e" "CMD=cargo +3a2610c2a16575649896925631bf8cec4f4b1961-alt check --frozen --all --all-targets" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-m" "2G" "crater"` Sep 10 20:12:15.088 INFO blam! 9615028fa4bc792a25a966fb6f4df9421f8b2212c53ccf7893632b3df09f7e01 Sep 10 20:12:15.090 INFO running `"docker" "start" "-a" "9615028fa4bc792a25a966fb6f4df9421f8b2212c53ccf7893632b3df09f7e01"` Sep 10 20:12:16.014 INFO kablam! usermod: no changes Sep 10 20:12:16.062 INFO kablam! Checking discard v1.0.3 (file:///source) Sep 10 20:12:16.585 INFO kablam! warning: unused `DiscardOnDrop` which must be used Sep 10 20:12:16.585 INFO kablam! --> src/lib.rs:251:9 Sep 10 20:12:16.585 INFO kablam! | Sep 10 20:12:16.585 INFO kablam! 251 | DiscardOnDrop::new(Foo::new()); Sep 10 20:12:16.585 INFO kablam! | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Sep 10 20:12:16.585 INFO kablam! | Sep 10 20:12:16.585 INFO kablam! = note: #[warn(unused_must_use)] on by default Sep 10 20:12:16.585 INFO kablam! = note: Sep 10 20:12:16.585 INFO kablam! Sep 10 20:12:16.585 INFO kablam! The DiscardOnDrop is unused, which causes it to be immediately discarded. Sep 10 20:12:16.586 INFO kablam! You probably don't want that to happen. Sep 10 20:12:16.586 INFO kablam! Sep 10 20:12:16.586 INFO kablam! How to fix this: Sep 10 20:12:16.586 INFO kablam! Sep 10 20:12:16.586 INFO kablam! * Store the DiscardOnDrop in a variable or data structure. Sep 10 20:12:16.586 INFO kablam! Sep 10 20:12:16.586 INFO kablam! * Or use the DiscardOnDrop::leak function which will cause it to not be Sep 10 20:12:16.586 INFO kablam! discarded (this *will* leak memory!). Sep 10 20:12:16.586 INFO kablam! Sep 10 20:12:16.586 INFO kablam! See the documentation for more details. Sep 10 20:12:16.586 INFO kablam! Sep 10 20:12:16.586 INFO kablam! Sep 10 20:12:16.734 INFO kablam! Finished dev [unoptimized + debuginfo] target(s) in 0.70s Sep 10 20:12:16.750 INFO kablam! su: No module specific data is present Sep 10 20:12:18.018 INFO running `"docker" "rm" "-f" "9615028fa4bc792a25a966fb6f4df9421f8b2212c53ccf7893632b3df09f7e01"` Sep 10 20:12:18.140 INFO blam! 9615028fa4bc792a25a966fb6f4df9421f8b2212c53ccf7893632b3df09f7e01