Recipe and Sources in a Different Repo

In the previous section, we fetched the sources of our library from an external repository. It is a typical workflow for packaging third party libraries.

There are two different ways to fetch the sources from an external repository:

Using the source() method as we displayed in the previous section:

from conans import ConanFile, CMake, tools

class HelloConan(ConanFile):
    ...

    def source(self):
        self.run("git clone https://github.com/conan-io/hello.git")
        ...

You can also use the tools.Git class:

from conans import ConanFile, CMake, tools

class HelloConan(ConanFile):
    ...

    def source(self):
        git = tools.Git(folder="hello")
        git.clone("https://github.com/conan-io/hello.git", "master")
        ...

Using the scm attribute of the ConanFile:

Warning

This is a deprecated feature. Please refer to the Migration Guidelines to find the feature that replaces this one.

from conans import ConanFile, CMake, tools

class HelloConan(ConanFile):
     scm = {
        "type": "git",
        "subfolder": "hello",
        "url": "https://github.com/conan-io/hello.git",
        "revision": "master"
     }
    ...

Conan will clone the scm url and will checkout the scm revision. Head to creating package documentation to know more details about SCM feature.

The source() method will be called after the checkout process, so you can still use it to patch something or retrieve more sources, but it is not necessary in most cases.