BEIRUT—The lead judge investigating Lebanon’s massive port explosion last year issued an arrest warrant on Thursday for a former minister who failed to appear for questioning, the state-run National News agency reported. It was the first such warrant in the year-old probe that has hit many snags, particularly in implicating senior government officials in what was one of the largest non-nuclear explosions ever recorded. It’s unclear how authorities will respond to the warrant. Youssef Fenianos, the former public works minister, is one of a number of former government officials who have declined to appear before investigating judge Tarek Bitar. Bitar has charged Fenianos and three other former senior government officials with intentional killing and negligence that led to the deaths of more than 200 people in the blast and over 6,000 injured. Bitar also summoned the former and current security chiefs. The former prime minister has also refused to appear …