There are multiple synonyms for the phrase "is a fiasco". Firstly, "is a debacle" means a disastrous failure or a complete collapse. Secondly, "is a catastrophe" represents a total failure or a major disaster. Thirdly, "is a shambles" refers to a situation marked by confusion, disorder, and failure. Fourthly, "is a disaster" represents a sudden event resulting in great damage or loss. Lastly, "is a mess" means a confusing or untidy situation that can lead to failure. Therefore, these synonyms can be used interchangeably to convey the message of a significant failure in any given situation.