"Stacking" extras without invoking pip conflict resolution

[silv-io]

We have recently switched from using setup.cfg to pyproject.toml. In our setup.cfg, we had "stacked" extras like this:

base-runtime:
    package

runtime:
    %(base-runtime)s
    other-package

So, installing the extra runtime meant that all the packages in base-runtime are also installed.

Now, with the pyproject.toml, to do this I've only found #3627, where it is suggested to depend on project[base-runtime] in the runtime extra.

However, what this does is, instead of just inserting all the dependencies of base-runtime in runtime, it invokes an extra conflict resolution step via pip.

With a sufficiently big enough set of dependencies and across projects which depend on each other, this makes using tools like pip-tools to create dependency pins a very slow process. (Tenfold increase from 4.5 minutes to 45 minutes).

So, is there a way to make the stacking of extras work like with the setup.cfg (presumably just inserting the strings into the array of the extra)?

[abravalheri]

Hi @silv-io, the %(base-runtime)s syntax is a feature of Python's configparser module. There is no equivalent for TOML (the TOML syntax does not include interpolation features).

So I am afraid that there is no way to achieve that, other than project[base-runtime] (which depends on pip).