missing astropy in build 189

[route2021]

After installing build 189 I am missing astropy !

[holzschu]

I'm going to have a look. I guess the automatic install script has failed silently. Is the error message providing information?

[route2021]

import astropy -> ModuleNotFoundError: No module named 'astropy'

and not listed with !pip list

[holzschu]

Oh, this one is interesting. astropy has a dependency on jinja2, jinja2 has a line that says: from markupsafe import Markup, escape, soft_unicode.

Except markupsafe 2.1.0 has removed soft_unicode, so this line breaks.

But astropy does not actually require jinja2, and they've removed it from the build requirements: https://github.com/astropy/astropy/commit/8f6ab831fb8c44d8758318faa890aaaa4cb5ac25 https://github.com/astropy/astropy/commit/87e73fababde2e2576e1255de0ca45f213079683 (so the version on the repository would build, but not the one from pip)

The incompatibility between markupsafe and jinja2 is one of the most discussed questions over at jinja2 (and their pinned issue): https://github.com/pallets/jinja/issues/1585

So, my options seem to be:

• wait for astropy 5.0.2, with the fix
• install astropy from the repository (instead of the version from pip)
• figure out if I can replace jinja2 with Jinja
• downgrade markupsafe to 2.0.1 (which still has soft_unicode)

I'll probably go for option 2.

[holzschu]

Okay, that's more subtle than that. I already have the right version of jinja2, but because astropy listed jinja2==2.10.3 as a requirement, pip install pulls the outdated version of jinja2 and that is what breaks the install.

I forgot about option 2b: download the source, fix the source with a patch, build and install.

[route2021]

Thanks, it seems to work! You are doing a good job!

[holzschu]

And the virtual environment issue from #230 should also be fixed.