I do not have access to real-time information, and there were no specific details available about Clint Eastwood's reaction upon learning about the death of Sondra Locke. Sondra Locke was a longtime partner of Clint Eastwood, and they had a tumultuous relationship that ended in the late 1980s. It's important to note that any information about Clint Eastwood's reaction to her death might be found in news reports or statements made by his representatives after 2023. I recommend checking recent news sources for the most up-to-date information on this topic.