Open Stack

Hi,

Recently we noted some projects modifying the ERROR_ON_CLONE environment
variable in devstack gate jobs.  It is never acceptable to do that.  It
is also not acceptable to read its value and alter a program's behavior.

Devstack is used by developers and users to set up a simple OpenStack
environment.  It does this by cloning all of the projects' git repos and
installing them.

It is also used by our CI system to test changes.  Because the logic
regarding what state each of the repositories should be in is
complicated, that is offloaded to Zuul and the devstack-gate project.
They ensure that all of the repositories involved in a change are set up
correctly before devstack runs.  However, they need to be identified in
advance, and to ensure that we don't accidentally miss one, the
ERROR_ON_CLONE variable is checked by devstack and if it is asked to
clone a repository because it does not already exist (i.e., because it
was not set up in advance by devstack-gate), it fails with an error
message.

If you encounter this, simply add the missing project to the $PROJECTS
variable in your job definition.  There is no need to detect whether
your program is being tested and alter its behavior (a practice which I
gather may be popular but is falling out of favor).

-Jim