执行“go mod tidy”报错下错误，执行“go clean -modcache”和删除“go env GOMODCACHE”指定目录均无效：
SECURITY ERROR
go.sum database server misbehavior detected!old database:go.sum database tree3397826xyyhzdyAOat5li/EXx/MK1gONQf3LAGqArhBLzQVQt8=— sum.mooon.com ZD16BsDeu0l8HWHTrM3Axa9jy5Ctbbmj9FZ1AowqytSa22OZ7Se98hXT+88+mjuCAIY5KSAG/nV26LayhI5OyaA3cAb=new database:go.sum database tree3398774MgvgQR/7OUAeth2F6s7qHqgBX7QNBIKhXfeN7iFPBes=— sum.mooon.com ZD16BtxccgOLtLlxqG5rx6vhz8vPBkqUTpW+loMoojYBqWcEeVWnxkKAMFtH2ynJrlXsOLLBfABqBJTxhyswvyh1mAe=proof of misbehavior:duuII5nfe1EhWYdzwvAkuwY/teHJYPtw8Ip1Z/ebbOt= internal error: generated inconsistent proof
删除项目的 go.sum 也不一定能解决，打新的 tag 可能也无用。可尝试删除文件 rm $(go env GOMODCACHE)/…/sumdb/sum.mooon.com/latest 后重试，测试解决了此问题。
报这个错误的源代码文件 https://github.com/golang/mod/blob/master/sumdb/client.go ：
// checkTrees checks that older (from olderNote) is contained in newer (from newerNote).
// If an error occurs, such as malformed data or a network problem, checkTrees returns that error.
// If on the other hand checkTrees finds evidence of misbehavior, it prepares a detailed
// message and calls log.Fatal.
func (c *Client) checkTrees(older tlog.Tree, olderNote []byte, newer tlog.Tree, newerNote []byte) error {thr := tlog.TileHashReader(newer, &c.tileReader)h, err := tlog.TreeHash(older.N, thr)if err != nil {if older.N == newer.N {return fmt.Errorf("checking tree#%d: %v", older.N, err)}return fmt.Errorf("checking tree#%d against tree#%d: %v", older.N, newer.N, err)}if h == older.Hash {return nil}// Detected a fork in the tree timeline.// Start by reporting the inconsistent signed tree notes.var buf bytes.Bufferfmt.Fprintf(&buf, "SECURITY ERROR\n")fmt.Fprintf(&buf, "go.sum database server misbehavior detected!\n\n")indent := func(b []byte) []byte {return bytes.Replace(b, []byte("\n"), []byte("\n\t"), -1)}fmt.Fprintf(&buf, "old database:\n\t%s\n", indent(olderNote))fmt.Fprintf(&buf, "new database:\n\t%s\n", indent(newerNote))// The notes alone are not enough to prove the inconsistency.// We also need to show that the newer note's tree hash for older.N// does not match older.Hash. The consumer of this report could// of course consult the server to try to verify the inconsistency,// but we are holding all the bits we need to prove it right now,// so we might as well print them and make the report not depend// on the continued availability of the misbehaving server.// Preparing this data only reuses the tiled hashes needed for// tlog.TreeHash(older.N, thr) above, so assuming thr is caching tiles,// there are no new access to the server here, and these operations cannot fail.fmt.Fprintf(&buf, "proof of misbehavior:\n\t%v", h)if p, err := tlog.ProveTree(newer.N, older.N, thr); err != nil {fmt.Fprintf(&buf, "\tinternal error: %v\n", err)} else if err := tlog.CheckTree(p, newer.N, newer.Hash, older.N, h); err != nil {fmt.Fprintf(&buf, "\tinternal error: generated inconsistent proof\n")} else {for _, h := range p {fmt.Fprintf(&buf, "\n\t%v", h)}}c.ops.SecurityError(buf.String())return ErrSecurity
}