import os
import subprocess

def have_needed_dot_support():
  if not os.path.exists('/usr/bin/dot'):
    return False

  try:
    ld_cmd = subprocess.Popen(['/usr/bin/dot', '-T?'],
                              stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE)
    ld_err = ld_cmd.stderr.read().decode()
    ld_cmd.wait()
  except:
    return False

  return 'pdf' in ld_err

if not have_needed_dot_support():
  config.unsupported = True