qtpy dependencies automatically get inappropriate version constraints

[smathot]

When qtpy is a dependency, conda build appears to automatically add version constraints that result in incompatibility. For example, building python-qnotifications results in the following index.json:

{
  "arch": null,
  "build": "py_2",
  "build_number": 2,
  "depends": [
    "pyqt >=5.12.3,<5.13.0a0",
    "python",
    "qt >=5.12.5,<5.13.0a0",
    "qtpy"
  ],
  "license": "GNU General Public License v3 (GPLv3)",
  "name": "python-qnotifications",
  "noarch": "python",
  "platform": null,
  "subdir": "noarch",
  "timestamp": 1577968165878,
  "version": "2.0.3"
}

This is incompatible with Python 2, for which these versions of PyQt are not available. This happens for all packages that have qtpy as a run dependency, which right now are python-qnotifications and python-qdatamatrix. I'm building with conda-build 3.18.11 and conda 4.7.12 on Ubuntu 19.10.

As a (deeply unsatisfying) workaround, I'm manually removing these version constraints before uploading the package. That works.

[smathot]

This also affects the python-qosf package.

[dschreij]

This may be complicated by the fact that Python 2 is EOL and so these safeguards are there with good reasons. Wouldn't using an older version of qtpy also fix this?

[dschreij]

I posted this issue in the conda-build repository (conda/conda-build#3864). They stated this has to do with https://github.com/conda-forge/pyqt-feedstock/blob/master/recipe/meta.yaml#L33.
Do you also get the packages from the conda-forge channel (Which is the channel for community packages). Related to this, there is a request now to make OpenSesame an official conda-forge package. How do you feel about this?

[smathot]

Do you also get the packages from the conda-forge channel (Which is the channel for community packages).

Yes, I added cogsci and conda-forge as channels.

It was not clear to me from the discussion here whether we found a solution for this?

Related to this, there is a request now to make OpenSesame an official conda-forge package. How do you feel about this?

I'm worried that this will take more time than we anticipate now, so for the moment let's not do this, and focus on things that have priority. There's also not that much to gain, because the few users of OpenSesame that use Anaconda can simply add the cogsci channel. In the long term though, I'm of course in favor of this.

[dschreij]

It was not clear to me from the discussion here whether we found a solution for this?
That link point to a 404