On Thu, May 5, 2022, 4:09 AM Daniel P. Berrangé <berrange@redhat.com> wrote:

> On Wed, May 04, 2022 at 03:38:45PM -0400, John Snow wrote:
> > Howdy!
> >
> > So, I want to finally delete python/qemu/qmp from qemu.git, and this
> > creates a small problem -- namely, iotests needs access to it in order
> > to run the python-based tests.
> >
> > What I think needs to happen is that we create a virtual environment
> > that installs python/qemu/. The reason this cannot be done with
> > PYTHONPATH alone anymore is because the qmp package itself won't be
> > there anymore, we need an installer like `pip` to actually fetch it
> > for us and put it somewhere. (i.e., we need to process the
> > dependencies of python/qemu now and can't treat it as a pre-installed
> > location.)
>
> Having pip fetch it on the fly creates a problem for RPM builds,
> because the koji build env has no network access. We will, however,
> have an RPM of python-qemu-qmp installed on the host system though.
> IOW we need to be able to run iotests using system python and its
> installed libs, not a virtual env.  So if we do anything with a
> virtual env, it will need to be optional I believe.
>

Hm, do we need iotests during an rpm build? Is it because of "make check"?

It's possible to create a venv and run pip in no-network mode, too. If the
package we want is installed on the system or otherwise in pip's cache,
it'll succeed without network. If the dependencies require a qemu.qmp
that's too new, the pip install will just fail instead.

I have to test a way to craft a pip statement that's network *optional*
though. i.e. try to fetch and fall back to local otherwise. I think it's
worth trying to keep the environment setup code unified, and always use a
venv.

I think this is tractable, though.