an employee can not breach the contract by leaving the job because your employer will take it from your salary. But, an employer can terminate you and there is nothing you can do about it because your kicked out of the country within 1-2 months. So it's pointless to file a lawsuit.

I've seen this happen to a guy from Germany. His contract was for 3 years and the government terminated it after 1 1/2 years. It may be a good idea to keep a nest or money. Or, if you fail your health exam the immigration will not award you your Qatar ID. Therefore, you get kicked out of the country automatically. That's when you will question yourself why did you leave your other job and sell all your stuff for nothing.