Include testing configurations that mirror production environments to catch issues that might only manifest in release builds. For example, testing with panic=abort can reveal issues that wouldn't appear when testing with the default panic=unwind setting. Similarly, when using specialized testing tools like Miri, configure the appropriate flags to ensure comprehensive validation under realistic conditions. Example: ```yaml - name: test all --all-features panic=abort run: | RUSTFLAGS="$RUSTFLAGS -C panic=abort -Zpanic-abort-tests" cargo nextest run --workspace --all-features --tests ``` When adding new test configurations, always preserve existing environment variables by appending to them rather than replacing them entirely, which ensures that other important configurations remain intact.