"If I sell now I will definitely have capital gains..."
I assume you're stating that because the current price of the stock is more than what you paid for it. If you sold right now you may or may not have capital gains and you won't know that until you receive your Schedule K-1. That's because the activity shown on your Schedule K-1 changes your basis from its original purchase price. Very broadly, distributions of cash from the fund lower your basis (and are not income), losses attributed to your shares decrease your basis and income attributed to you increase your basis. Because of this there is no "double taxing" of income. So if the partnership happens to have income, taxed at ordinary rates, that lowers your capital gain, taxed at capital gains rates.
