How to Use MixinTrace to Report a Bug to a Mod Author

Mod authors cannot fix what they cannot see. MixinTrace gives you the precise mixin information they need, so a good report gets a fix much faster.

Capture the full crash report

Reproduce the crash, then grab the complete file from your crash-reports folder rather than a screenshot of the popup. The MixinTrace section is only useful in full — partial copies lose the config names and target classes.

Pull out the key lines

From the MixinTrace section, copy: the target class that was being patched, the mixin class name that appears in the failing stack frame, and its configuration name. Also note your full mod list and the exact action that triggered the crash (opening a GUI, breaking a block, joining a world).

Write the report

Post to the mod's issue tracker with: a one-line summary, steps to reproduce, the extracted mixin details, and the full crash report as an attachment or paste. Mention any other mods that patch the same target class, since that points at a conflict rather than a standalone bug. Do not trim the log to save space — authors search it for their own identifiers. With the mixin and config names in hand, they can jump straight to the offending injection instead of guessing.