Running a Linux distribution via proot-distro on Termux is a weird experience. While the filesystem is properly isolated from the host, the process view isn't, so traditional init systems can't be used in proot(not even Rich Felker's minimal init). I had to strip Felker's init down to literally this as a working starting point:

int main()

{

return execve("/etc/rc", (char *[]){ "rc", 0 }, (char *[]){ 0 });

}