Re: [PATCH v4 05/24] python: add qemu package installer

[John Snow]

On 2/16/21 9:23 PM, Cleber Rosa wrote:
> On Thu, Feb 11, 2021 at 01:58:37PM -0500, John Snow wrote:
> > Add setup.cfg and setup.py, necessary for installing a package via
> > pip. Add a rst document explaining the basics of what this package is
>
> Nitpick 1: setup.cfg and setup.py are indeed used by pip, your
> statement is correct.  But, it hides the fact that these can be used
> without pip.  On a source tree based install, you may want to simply
> use "python setup.py develop" to achieve what "pip install -e" would
> do (without pip ever entering the picture).

This is intentional. pip and setup.py actually use different pathways 
that are not identical. I do not recommend you call setup.py directly 
anymore. Once pyproject.toml is more widespread, there won't even *be* a 
setup.py.

> Nitpick 2: while most people will understand what you mean by "rst
> document", I believe that "Add a README file in reStructuredText
> format" would be more obvious.

Sure.

> > for and who to contact for more information. This document will be used
> > as the landing page for the package on PyPI.
> >
> > I am not yet using a pyproject.toml style package manifest, because
> > "editable" installs are not defined by PEP-517 and pip did not have
> > support for this for some time; I consider the feature necessary for
> > development.
>
> I'm glad you kept it like this... I bet there's going to be another
> PEP out, replacing the status quo, by the time I finish this review.

Actually, between writing this series last year and this latest respin, 
pip supports editable installs for pyproject.toml distributions now :)

...but I was still hesitant to take the leap, because maybe that's still 
too modern for the 3.6-based distributions we target and support.

...And I left the message alone, because I didn't re-research the exact 
reason I'm not using pyproject.toml now. Eh.

> > Use a light-weight setup.py instead.
> >
> > Signed-off-by: John Snow <jsnow@redhat.com>
> > ---
> >   python/PACKAGE.rst | 32 ++++++++++++++++++++++++++++++++
> >   python/setup.cfg   | 19 +++++++++++++++++++
> >   python/setup.py    | 23 +++++++++++++++++++++++
> >   3 files changed, 74 insertions(+)
> >   create mode 100644 python/PACKAGE.rst
> >   create mode 100644 python/setup.cfg
> >   create mode 100755 python/setup.py
> >
> > diff --git a/python/PACKAGE.rst b/python/PACKAGE.rst
> > new file mode 100644
> > index 00000000000..0e714c87eb3
> > --- /dev/null
> > +++ b/python/PACKAGE.rst
> > @@ -0,0 +1,32 @@
> > +QEMU Python Tooling
> > +===================
> > +
> > +This package provides QEMU tooling used by the QEMU project to build,
> > +configure, and test QEMU. It is not a fully-fledged SDK and it is subject
> > +to change at any time.
> > +
> > +Usage
> > +-----
> > +
> > +The ``qemu.qmp`` subpackage provides a library for communicating with
> > +QMP servers. The ``qemu.machine`` subpackage offers rudimentary
> > +facilities for launching and managing QEMU processes. Refer to each
> > +package's documentation
> > +(``>>> help(qemu.qmp)``, ``>>> help(qemu.machine)``)
> > +for more information.
> > +
>
> This gives the impression that those are the only subpackages (and
> they were).  Better to reword it taking into account the qemu.utils
> subpackage and possibly others (leave it open so that it doesn't rot
> so quickly).

Intentional again. I don't, for the moment, consider that utils package 
something "supported" in the public sense, so I didn't feel the urge to 
draw attention to it.

> - Cleber.