conda-forge recipe now requires Python >= 3.7, < 3.8.0a0 -- this prevents installation from conda into QIIME 2 environments

[fedarko]

This seems to be due to dependencies, because the rest of the code should support Python 3.6 up until (but not including) Python 3.10.

I don't mind the >= 3.7 part too much, but the < 3.8.0a0 restriction causes an error when we try to install Qurro using conda into a QIIME 2 environment of at least 2021.4 (when QIIME 2 switched to Python 3.8.x). I have a sinking feeling that the >= 3.7 thing means that Qurro will also not be installable into older QIIME 2 environments than 2021.4, because those used Python 3.6.x.

Qurro is still installable through pip (and the conda-forge install still works in fresh environments), but it would be good to fix this if possible. I suspect the problem boils down to finding which dependency / dependencies are imposing these restrictions and modifying how we rely on them.

Edit: yep it's the altair pin that's causing this -- we can directly test this by running mamba install --dry-run -c conda-forge altair=3.1.0, which gives us the same error about needing Python >= 3.7, < 3.8.0a0. This issue (along with the upper limit on Python 3.10) should therefore be fixed when #216 is addressed.

[timyerg]

Hello!

Qurro is still installable through pip (and the conda-forge install still works in fresh environments),

Now installation of qurro via pip downgrades scipy and several other packages which leads to errors in qiime2 commands. Tested with freshly installed qiime2-amplicon-2023.9 and 2024.2. Still works in 2023.5

Conda installation gives an error:

Could not solve for environment specs
The following packages are incompatible
├─ pin-1 is installable and it requires
│  └─ python 3.8.* , which can be installed;
└─ qurro is not installable because there are no viable options
   ├─ qurro [0.6.0|0.7.0|0.7.1] would require
   │  └─ python >=3.6,<3.7.0a0 , which conflicts with any installable versions previously reported;
   └─ qurro [0.6.0|0.7.0|0.7.1|0.8.0] would require
      └─ python >=3.7,<3.8.0a0 , which conflicts with any installable versions previously reported.

Pins seem to be involved in the conflict. Currently pinned specs:
 - python 3.8.* (labeled as 'pin-1')

[fedarko]

Thanks for letting me know -- sorry for the inconvenience. I guess the situation has changed in the past few years.

For now, the most reliable workaround will be using Qurro with older versions of QIIME 2 (or just outside of QIIME 2). I hope to address #216 when I get some time, which should make it feasible to remove the version pins and make Qurro interoperable with more versions of QIIME 2. Sorry I can't provide a more satisfying resolution at this time...