Broken Pipe Error when Buffer is Full

[jakhax]

Steps to reproduce

	opt := &spawn.Opt{
		Timeout:2000,
		MaxBufferSize:150,
	};
	var stdin io.Reader
	stdout,stderr,errX :=  spawn.Spwan(opt,"python3",[]string{"-c",`while True:print("111111111111")`},stdin)

Error

Traceback (most recent call last):
  File "<string>", line 1, in <module>
BrokenPipeError: [Errno 32] Broken pipe

• Am not sure if this only happens on certain environments(mine is ubuntu 18.04) will investigate this later.