v2_linter.md

Linter to help migration to Conan v2

On our path to Conan v2 we are leveraging on custom Pylint rules. This linter will run for every pull-request that is submitted to the repository and will raise some warnings and errors that should be addressed in order to migrate the recipes to Conan v2.

It is important to note that these rules are targetting Conan v2 compatibility layer, their purpose is to fail for v1 syntax that will be no longer available in v2. Even if the syntax if perfectly valid in Conan v1, the recipe might fail here because it is not v2-compliant.

Note.- Some of the errored checks might be just plain Python syntax errors, while others might be related to the custom rules added by us.

Here you can find some examples of the extra rules we are adding:

Import ConanFile from conan

The module conans is deprecated in Conan v2. Now all the imports should be done from module conan:

from conan import ConanFile

Import tools from conan

All v2-compatible tools are available in module conan.tools under different submodules. Recipes should start to import their tools from this new module. Some of the new tools accept new argument, please, check the Conan documentation.

For example, the cross_building tool now should be used like:

from conan.tools.build import cross_building

...
class Recipe(ConanFile):

    def test(self):
        if not cross_building(self):
            pass