I was experiencing a hang when calling setreuid from a thread on musl 1.2.1 as well as on master with these patches applied. I have attached a Go program which hangs when run as the root user outputting only: main.go:31: Calling setreuid Whereas with glibc the setreuid call completes successfully, with the following output: test.go:31: Calling setreuid test.go:40: Running command test.go:45: root test.go:46: Command complete I am happy to help troubleshoot the issue, yours kindly, Jesse