zurba@zurba-laptop:~/Develop/make$ gcc test.c -o test
zurba@zurba-laptop:~/Develop/make$ chmod 4755 test
zurba@zurba-laptop:~/Develop/make$ ./test
Must be run as root.
clone: Operation not permitted
Clone failed. PID namespaces ARE NOT supported
zurba@zurba-laptop:~/Develop/make$ sudo ./test
[sudo] password for zurba:
clone: Operation not permitted
Clone failed. PID namespaces ARE NOT supported
zurba@zurba-laptop:~/Develop/make$ strace ./test
execve("./test", ["./test"], [/* 43 vars */]) = 0
brk(0)                                  = 0x1a9b000
uname({sys="Linux", node="zurba-laptop", ...}) = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x400cc000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=111681, ...}) = 0
mmap2(NULL, 111681, PROT_READ, MAP_PRIVATE, 3, 0) = 0x40172000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/arm-linux-gnueabi/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0Mm\1\0004\0\0\0"..., 512) = 512
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x401fb000
fstat64(3, {st_mode=S_IFREG|0755, st_size=876656, ...}) = 0
mmap2(NULL, 918832, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x40286000
mprotect(0x40359000, 32768, PROT_NONE)  = 0
mmap2(0x40361000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0xd3) = 0x40361000
mmap2(0x40364000, 9520, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x40364000
close(3)                                = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40029000
set_tls(0x400294c0, 0x40029b98, 0x400ae050, 0x400294c0, 0x401fb470) = 0
mprotect(0x40361000, 8192, PROT_READ)   = 0
mprotect(0x10000, 4096, PROT_READ)      = 0
mprotect(0x400ad000, 4096, PROT_READ)   = 0
munmap(0x40172000, 111681)              = 0
getuid32()                              = 1000
write(2, "Must be run as root.\n", 21Must be run as root.
)  = 21
clone(child_stack=0xbed0226c, flags=0x60000000|SIGCHLD) = -1 EPERM (Operation not permitted)
write(2, "clone: Operation not permitted\n", 31clone: Operation not permitted
) = 31
write(2, "Clone failed. PID namespaces ARE"..., 47Clone failed. PID namespaces ARE NOT supported
) = 47
wait4(-1, NULL, 0, NULL)                = -1 ECHILD (No child processes)
exit_group(0)                           = ?
zurba@zurba-laptop:~/Develop/make$