automation: install python3-venv Debian package
Debian's python install has a crippled venv by default, as it is
lacking ensurepip. When you try to run `python3 -m venv` it tells
you to install `python3-venv`. So this commit does that in our
automation environment so we can fully test installing Mercurial
using venv+pip with the system Python.
Differential Revision: https://phab.mercurial-scm.org/D7229
from __future__ import absolute_import, print_function
import sys
def flush():
sys.stdout.flush()
sys.stderr.flush()
globalvars = {}
lines = sys.stdin.readlines()
while lines:
l = lines.pop(0)
if l.startswith('SALT'):
print(l[:-1])
elif l.startswith('>>> '):
snippet = l[4:]
while lines and lines[0].startswith('... '):
l = lines.pop(0)
snippet += l[4:]
c = compile(snippet, '<heredoc>', 'single')
try:
flush()
exec(c, globalvars)
flush()
except Exception as inst:
flush()
print(repr(inst))