Some python programs are in python-modules

[Aleksanaa]

Problem

I just discovered that in pkgs/development/python-modules:

=> grep -r 'mainProgram' . | wc -l
1210

=> find . -maxdepth 1 -type d | wc -l
7526

So 1210 out of 7526 python modules have a mainProgram. And also a lot of them (most?) don't have a toPythonApplication in top-level.

So now we have 3 approaches to package a python application:

1. use python3Packages.buildPythonApplication, and put it in pkgs/by-name.
2. use buildPythonPackage and put in pkgs/development/python-modules, and add a toPythonApplication entry in all-packages.nix
3. use buildPythonPackage and put in pkgs/development/python-modules, and let users write python3Packages.foo

Solution

If the upstream documentation doesn't mention it can be used as a python module, then only 1 is correct. If upstream doesn't mention but there do have some examples, then toPythonModule should be used (but we can also tolerate toPythonApplication and put in python-modules).

If it's primarily used as a module, but also has some useful executables, then 2 is correct. If it's only used as a python module, or the executable doesn't have external use cases (for example, is serving the needs of the module), then only 3 is correct.

This should be explicitly documented and anti-patterns should be removed

[Aleksanaa]

ping @natsukium @fabaff

[AndersonTorres]

Hum, my suspects about git-filter-repo have some basis...

[fabaff]

mainProgram was added automatically (in most cases) with #297084. I assume that most of the 1210 hits were coming for that PR.

[dotlambda]

I don't think having a top-level alias is a necessity. If any of those are only tools and don't provide an API, they should be removed from python3Packages. But having mainProgram is not a sufficient condition.