How many threads will be used in a Go program if GOMAXPROCS=1 is set?

Setting the environment variable GOMAXPROCS=1 in a Go program will use exactly one OS thread to run all goroutines. This means that the Go scheduler will run goroutines sequentially on a single CPU core, not utilizing parallelism across multiple cores. There may be many goroutines, but they will be executed on a single thread, which limits parallel execution.