You're thinking of the unfortunate Guillaume le Gentil who attempted to observe the 6 June 1761 transit of Venus from Pondicherry in India. He almost made it but when his ship was approaching Pondicherry they learned that the British had occupied it, and had to turn back for Mauritius. He couldn't make the proper measurements on board ship where he found himself on 6 June.

He decided to stick around in Asia for the intervening eight years before the next transit on 4 June 1769. After selecting Manila for his observation he was rebuffed by the Spanish. Luckily Pondicherry had been returned to France so he set his equipment there. The days leading up to the transit were bright and sunny.

4 June was overcast and he couldn't make his measurements.

When he returned to Paris he learnt that he had been declared legally dead, his wife had remarried, and his estate had been distributed to his heirs.