Credentials input not working with contex.run from within a Devcontainer #1069

While I found several different issues where something related to stdin did or does not work - this one does not seem to be covered, yet:

What happens:
Entering user name/pw from stdin to programm started with c.run does not work. What (mostly) happens:

1. First character gets swallowed somehow. Have to press the first character twice. Found some issues about that one. And: Looks ike in_stream=False makes the first character appear on the first key press.
2. PW entry not working: When running inside the devcontainer, after pressing enter to confirm the user name, the password prompt is missing, and nothing happens when I press any key.

• pty=True/False does not seem to have an effect
• in_stream=False will avoid the 'first-character-gets-swallowed` problem, but still not fix the passwort-entry-problem

You should be able to use the following script to reproduce the issue - when executed from within a devcontainer in VSCode:

import shlex
import sys
import textwrap

from invoke import Context

INNER_SCRIPT = textwrap.dedent(
    """
    from getpass import getpass

    print('=== Please enter your USERNAME ===', flush=True)
    username = input()
    print('=== Please enter your PASSWORD ===', flush=True)
    password = getpass('')
    print(f'You entered username: {username}')
    print(f'You entered password: {password}')
    """
).strip()


print(">>> running via invoke Context.run(pty=True)")
cmd = f"{shlex.quote(sys.executable)} -c {shlex.quote(INNER_SCRIPT)}"
Context().run(cmd, in_stream=True)