This causes `upgrade-zulip-from-git`, as well as a no-option run of
`tools/build-release-tarball`, to produce a Zulip install running
Python 3, rather than Python 2. In particular this means that the
virtualenv we create, in which all application code runs, is Python 3.
One shebang line, on `zulip-ec2-configure-interfaces`, explicitly
keeps Python 2, and at least one external ops script, `wal-e`, also
still runs on Python 2. See discussion on the respective previous
commits that made those explicit. There may also be some other
third-party scripts we use, outside of this source tree and running
outside our virtualenv, that still run on Python 2.
The #! line processing interpreted the argument to pass to `env` as
"python2.7 -u", which obviously isn't a real program.
We fix this by setting the PYTHONUNBUFFERED environment variable
inside the program, which has the same effect.
Thanks to Dan Fedele for the bug report and suggested solution!
rht
Greg Price
Umair Khan
Taranjeet Singh
Tim Abbott
Eklavya Sharma
Steven Oud
Tim Abbott