RPM python bindings dependency

[nforro]

specfile currently depends on rpm which is not (and probably never will be) available on PyPI. That means whoever wants to install it using pip has to have RPM python bindings already installed (usually via a package manager).
We could instead depend on rpm-py-installer, but it's not a flawless solution.

[nforro]

One problem is, specifying rpm-py-installer as a dependency breaks dynamic buildrequires, because there is no python3dist(rpm-py-installer) in Fedora.

A solution that comes to mind is to continue depending on rpm and use an extra for rpm-py-installer, so users could install specfile with pip install specfile[rpm-py-installer] (or something similar).

[TomasTomecek]

how hard would it be to have rpm available on PyPI?

would it be too complicated to write a script and run it in GitHub action that would take care of that?

[nforro]

would it be too complicated to write a script and run it in GitHub action that would take care of that?

What do you mean exactly? I don't follow.

[TomasTomecek]

So, I understand that rpm-py-installer compiles the rpm python bindings locally on the fly. That's great but requires all build tools and everything.

Since you can have binary artifacts on PyPI, one could do that in a controlled environment (e.g. GitHub action) and upload the artifacts to PyPI as bdist_wheel.

Do you think that would work?

[nforro]

I'm not sure. The thing is, RPM python bindings are tied to a specific RPM version. So there would have to be a build for every RPM version ever released and the correct one would have to be chosen during installation.

If I understand it correctly, rpm-py-installer first tries to install matching bindings from a system package, and only if that's not possible it builds them from source (and in the worst case it builds RPM itself from source as well).

[nforro]

See also rpm-software-management/rpm#273

[TomasTomecek]

oh, didn't realize it works like that, thank you for educating me

I wish they changed their mind.

[nforro]

A better solution that works with dynamic buildrequires is to substitute rpm-py-installer with rpm in setup.cfg in %prep (it works because %prep is executed before %generate_buildrequires):

%prep
%autosetup -p1 -n specfile-%{version}
sed -i 's/rpm-py-installer/rpm/' setup.cfg

%generate_buildrequires
%pyproject_buildrequires -x testing