ERROR: test_pty_serial_open_slave (test_pty.Test_Pty_Serial_Open.test_pty_serial_open_slave)
    raise OSError('out of pty devices')
OSError: out of pty devices
ERROR: test_pty_serial_read (test_pty.Test_Pty_Serial_Open.test_pty_serial_read)
    raise OSError('out of pty devices')
OSError: out of pty devices
ERROR: test_pty_serial_write (test_pty.Test_Pty_Serial_Open.test_pty_serial_write)
    raise OSError('out of pty devices')
OSError: out of pty devices
FAILED (errors=3, skipped=5)
>>> ERROR: py3-pyserial: check failed