"gn gen out/Build" - generating build files for fluoride(system/bt) failed!!

[minjun]

I am trying to build the new Bluetooth stack Fluoride(system/bt) under ubuntu (currently 17.04 beta), and I am following https://android.googlesource.com/platform/system/bt/ . When I am trying the"Generate your build files " step, I find the "gn gen out/Default" command failed with the following error message:

minjun@localhost:~/fluoride/bt$ gn gen out/Default
Traceback (most recent call last):
  File "/home/minjun/bin/linux64/gn.py", line 38, in <module>
    sys.exit(main(sys.argv))
  File "/home/minjun/bin/linux64/gn.py", line 33, in main
    return subprocess.call([gn_path] + args[1:])
  File "/usr/lib/python2.7/subprocess.py", line 168, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 390, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 916, in _execute_child
    self.pid = os.fork()
OSError: [Errno 12] Cannot allocate memory

It seems too many processes are forked and there're enough memory for them. 

Does anyone know why this happens? Thank you!

[minjun]

I also tried the same procedure under ubuntu 14.04.5 LTS, and got the same results. 

Is there any underlying memory/cpu requirements for the "gn gen out/Default" command? 

BTW, what I have done are in VMware VMs..