Fix a few issues with generate_config

[saimn]

When using it with other packages (tried this with astroquery), this fixes several issues:

• Astropy modules where imported and then added to the config file.
• One module (astroquery.mpc) was added 3 times because it is imported in other modules.
• Astroquery instantiates its classes at import which causes a lot of warnings/logging messages, so I choose to silence all outputs.

[bsipocz]

One module (astroquery.mpc) was added 3 times because it is imported in other modules.

what do you mean exactly? It's imported into the pseudo module solarsystem, is that causing troubles? (what I don't understand that the same is done for the jpl modules, do those behave differently?)

Astroquery instantiates its classes at import which causes a lot of warnings/logging messages, so I choose to silence all outputs.

if there are obsessive logging/warnings, we can certainly look into that and do a cull. Could you provide examples?

[saimn]

what do you mean exactly? It's imported into the pseudo module solarsystem, is that causing troubles? (what I don't understand that the same is done for the jpl modules, do those behave differently?)

Yes, it happens when importing solarsystem.mpc for example, which creates a new mpc.Conf class. I think it happens because importing mpc fails because of astropy._erfa.core, and so the module import is not cached. And I just realized that I had updated astroquery but I had an old version installed in my site-packages, so with astroquery master the error is gone and it works correctly, without the multiple conf classes. Anyway I think it's still reasonable to have this change to be safe.

if there are obsessive logging/warnings, we can certainly look into that and do a cull. Could you provide examples?

Sure, this is only when filtering only deprecation warnings: https://gist.github.com/saimn/a18203a6ca86e6c573af0b53fb9b0d37

[bsipocz]

Glad to hear that master is being fixed, I recall a few back and forth of how to deal with those erfa things.

Sure, this is only when filtering only deprecation warnings: https://gist.github.com/saimn/a18203a6ca86e6c573af0b53fb9b0d37

Ahh, thanks. We should raise errors for deprecations, so if any of those are around that's a real issue (with the exception of deprecations coming from pyregion or html5lib). Could you report them back in an astroquery issue?

Most of those are legit warnings, and the rest is already on the radar to be cleaned up.

[embray]

While making changes in this function anyways, how does my idea in this comment sound #10877 (comment) ?

[pllim]

All these years, I didn't know this existed. 😱

astropy/astropy/utils/misc.py

Lines 62 to 64 in 079fcb7

	@contextlib.contextmanager
	def silence():
	"""A context manager that silences sys.stdout and sys.stderr."""

[pllim]

LGTM. Thanks!

[pllim]

@saimn , perhaps you should answer @embray 's question about #10877 (comment) before merge?

[saimn]

@pllim - I think I did so ?
I mean, @embray proposed a slightly different solution, but we can discuss that in #10877.

[pllim]

Okay then, let's continue discussion on the other issue. Thanks, everyone!