def _start_session(self, install=True):
self.session = Session()
self.session.start()
# Convenience so the caller doesn't have to tear down the
# session, unless it's being explicitly preserved.
if KEEP_SESSIONS:
print()
print()
print('KEEPING SESSION:', self.session.id, file=sys.stderr)
print()
else:
self.addCleanup(self.session.end)
if install:
self.session.call([self.python, 'setup.py', 'install'],
env=dict(LC_ALL='en_US.UTF-8'))
