resolve/config.go
func FindRuleWithOverride(c *config.Config, imp ImportSpec, lang string) (label.Label, bool) {
	rc := getResolveConfig(c)
	for i := len(rc.overrides) - 1; i >= 0; i-- {
		o := rc.overrides[i]
		if o.matches(imp, lang) {
			return o.dep, true
		}
	}
	return label.NoLabel, false
}
func FindRuleWithOverride(c *config.Config, imp ImportSpec, lang string) (label.Label, bool) {
	rc := getResolveConfig(c)
	for i := len(rc.overrides) - 1; i >= 0; i-- {
		o := rc.overrides[i]
		if o.matches(imp, lang) {
			return o.dep, true
		}
	}
	return label.NoLabel, false
}
// FindRuleWithOverride searches the current configuration for user-specified
// dependency resolution overrides. Overrides specified later (in configuration
// files in deeper directories, or closer to the end of the file) are
// returned first. If no override is found, label.NoLabel is returned.