Create Minimal Reproduction

An MRE is complete only when its documented command was run and produced the claimed observable result. Capture the original failure before reducing it: exact command, expected and actual result, relevant diagnostic, versions, OS/architecture, inputs, configuration, and state assumptions.

Work in a disposable directory. Start with the smallest artifact the ecosystem actually needs: a source file and compiler command when sufficient; otherwise a small project with its required manifest and configuration. DO NOT scaffold an application, retain private source, or add a dependency that does not affect the behavior.

Remove one independent element at a time and re-run the same oracle. Keep a removal only if the target behavior remains. For races or flakes, preserve the trigger, record sample count and failures, and state the observed rate; do not claim deterministic reproduction when it is not deterministic.