when running a command, stdin requires a keypress on Windows

[bevancollins]

I am wanting to pass a file to the stdin of a command on Windows
type file.txt | inv doecho

where:

import invoke

@invoke.task()
def doecho(ctx):
    ctx.run('more')

more is run but waits until a key is pressed and then executes as expected. This is nothing to do with more.. the same result can be seen when running cat from cygwin or anything else that reads from stdin