Golang error function arguments too large for new goroutine

No, none I know of.

I don't think you should be too aggressive tuning to avoid copying, but it appears from the source that this error is emitted when parameters exceed the usable stack space for a new goroutine, which should be kilobytes. The copying overhead is real at that point, especially if this isn't the only time these things are copied. Perhaps some struct either explicitly is larger than expected thanks to a large struct member (1kb array rather than a slice, say) or indirectly. If not, just using a pointer as you have makes sense, and if you're worried about creating garbage, recycle the structs pointed to using sync.Pool.