panic(err) — error from ConvertMySQLVersionToCommentVersion(

Error message

panic(err) — error from ConvertMySQLVersionToCommentVersion(config.DefaultMySQLVersion)

What it means

NewTestParser creates a Parser with Vitess's DefaultMySQLVersion converted to a parser comment version. If ConvertMySQLVersionToCommentVersion cannot map that default constant (e.g. the default version constant was bumped to an unrecognized string), it panics — a build/config-time invariant failure rather than a runtime user error.

Source

Thrown at go/vt/sqlparser/parser.go:399

func New(opts Options) (*Parser, error) {
	if opts.MySQLServerVersion == "" {
		opts.MySQLServerVersion = config.DefaultMySQLVersion
	}
	convVersion, err := ConvertMySQLVersionToCommentVersion(opts.MySQLServerVersion)
	if err != nil {
		return nil, err
	}
	return &Parser{
		version:        convVersion,
		truncateUILen:  opts.TruncateUILen,
		truncateErrLen: opts.TruncateErrLen,
	}, nil
}

func NewTestParser() *Parser {
	convVersion, err := ConvertMySQLVersionToCommentVersion(config.DefaultMySQLVersion)
	if err != nil {
		panic(err)
	}
	return &Parser{
		version:        convVersion,
		truncateUILen:  512,
		truncateErrLen: 0,
	}
}

View on GitHub (pinned to 01a25a7d17)

Solutions

Check config.DefaultMySQLVersion and make sure it is a valid dotted MySQL version string
Update ConvertMySQLVersionToCommentVersion to support the new default version
As a workaround in tests, construct &Parser{version: ...} directly with a known-good version

Example fix

// before
config.DefaultMySQLVersion = "99.99"
// after
config.DefaultMySQLVersion = "8.0.35"

Defensive patterns

Strategy: try-catch

Validate before calling

if _, err := sqlparser.ConvertMySQLVersionToCommentVersion(config.DefaultMySQLVersion); err != nil {
    // fix config.DefaultMySQLVersion before calling NewTestParser
}

Try / catch

defer func() {
    if r := recover(); r != nil {
        t.Fatalf("NewTestParser panicked (check config.DefaultMySQLVersion): %v", r)
    }
}()
p := sqlparser.NewTestParser()

Prevention

Keep config.DefaultMySQLVersion in lockstep with versions ConvertMySQLVersionToCommentVersion supports
Add a test that converts the default version at init/test time
Pin the version used in tests to a known-supported value

When it happens

Trigger: Calling NewTestParser() when config.DefaultMySQLVersion is not a string recognized by ConvertMySQLVersionToCommentVersion (malformed like "x.y", or too new/old to map).

Common situations: A config package change bumping DefaultMySQLVersion to an unsupported value while sqlparser's converter lags; tests using NewTestParser after a dependency merge.

Related errors

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/8ed13298edc64f04. Report an issue: GitHub.