by not enclosing the arguments for the process in a list, your strings all got interpreted as arguments to the run function. One of those is bufsize and it expects an integer. More info on the buffer in pipes: Pipeline (Unix) - Wikipedia
by not enclosing the arguments for the process in a list, your strings all got interpreted as arguments to the run function. One of those is bufsize and it expects an integer. More info on the buffer in pipes: Pipeline (Unix) - Wikipedia