Tunisians are suffering delays to salary payments and shortages of grains, medicines and sugar, a foretaste, some economists say, of a rapidly looming public finances crisis that looks increasingly hard to avert. Outside the Ettahrir district of Tunis, taxi driver Ahmed ben Salem stood in a long queue at a bakery that has cut its working times because supplies are more limited than in the past. “This isn’t my only failed shopping trip. For the past month, I go around the district every day looking for semolina. I go through all the shops but without hope,” he said. Any big hit to the standard …