There's already the quiet #BovrilRationing that @Knitronomicon led me to discover the other week. Given that Bovril and tomato #sandwich es are a staple, I can only say that the world is bleak at the moment.
As it's a shopping day, I should use a more shopping-oriented search engine than Bing. A quick e-Bay search for "fun bucket" reveals that a #FunBucket does not contain #Marmite, but something equally brown and bad tasting.