[QGIS-Developer] OSGeo4W: python libraries missing when installing plugins

[Tobias Wendorff]

Hi there,

sorry for the cross-post, but I believe, that both sides should work
together on this issue.

When installing QGIS on Windows the normal way (which doesn't need
the user get to know about all those expert settings and libraries),
you'll quickly run into the problem of missing Python libraries when
installing a plugin. Numpy, SciPy or mathlib are the most common
ones, but there's also well know ones, which can't get installed
automatically on Windows.

Perhaps we should setup rules for plugin developers to inform OSGeo4W,
which plugins might be required. Perhaps we should just "grep" through
all the repositories and find all the imports?

But even then, QGIS on Windows doesn't automatically install the missing
libraries. And even if QGIS would do (setuptools, pip, whatever), the
OSGeo4W-install would lose track about this and we even might get into
version chaos.

So we need a bi-directional way between QGIS and OSGeo4W installer.
Perhaps QGIS (or an additional QGIS plugin, hehe) could trigger
OSGeo4W installer silently to download the packages needed. So it might
keep track of it.

Right now, it's often hard work, since not all the libraries needed
have been added to OSGeo4W. Sure, the girls & guys do their best work
to add the missing libs upon request, but even then, you need to be
aware, WHICH plugin you need and you need to install it outside of
QGIS (at best practice, even BEFORE the installation in QGIS stars
because it might make QGIS instable, crash or both).

How can I help?

Best regards,
Tobias