Git

Warning

This tool is experimental and subject to breaking changes.

constructor

def __init__(self, conanfile, folder=".")

Construct a Git object, specifying the current directory, by default ".", the current working directory.

get_commit()

def get_commit(self)

Returns the current commit, with git rev-list HEAD -n 1 -- <folder>. The latest commit is returned, irrespective of local not commmited changes.

get_remote_url()

def get_remote_url(self, remote="origin")

Obtains the URL of the remote git remote repository, with git remote -v

commit_in_remote()

def commit_in_remote(self, commit, remote="origin")

Checks that the given commit exists in the remote, with branch -r --contains <commit> and checking an occurence of a branch in that remote exists.

is_dirty()

def is_dirty(self)

Returns if the current folder is dirty, running git status -s

get_repo_root()

def get_repo_root(self)

Returns the current repository top folder with git rev-parse --show-toplevel

clone()

ef clone(self, url, target="")

Does a git clone <url> <target>

checkout()

def checkout(self, commit)

Checkouts the given commit

get_url_and_commit()

def get_url_and_commit(self, remote="origin")

This is an advanced method, that returns both the current commit, and the remote repository url. This method is intended to capture the current remote coordinates for a package creation, so that can be used later to build again from sources from the same commit. This is the behavior:

  • If the repository is dirty, it will raise an exception. Doesn’t make sense to capture coordinates of something dirty, as it will not be reproducible. If there are local changes, and the user wants to test a local conan create, should commit the changes first (locally, not push the changes).

  • If the repository is not dirty, but the commit doesn’t exist in the given remote, the method will return that commit and the URL of the local user checkout. This way, a package can be conan create created locally, testing everything works, before pushing some changes to the remote.

  • If the repository is not dirty, and the commit exists in the specified remote, it will return that commit and the url of the remote.

Example: Implementing the scm feature

This example is the new way to implement the scm feature (to be removed in Conan 2.0), using this new Git capabilities.

Assume we have this project with this layout, in a git repository:

├── conanfile.py
├── CMakeLists.txt
├── src
│   └── hello.cpp

And the conanfile.py is:

import os
from conan import ConanFile
from conan.tools.scm import Git
from conan.tools.files import load, update_conandata


class Pkg(ConanFile):
    name = "pkg"
    version = "0.1"

    def export(self):
        git = Git(self, self.recipe_folder)
        scm_url, scm_commit = git.get_url_and_commit()
        # we store the current url and commit in conandata.yml
        update_conandata(self, {"sources": {"commit": scm_commit, "url": scm_url}})

    def layout(self):
        self.folders.source = "."

    def source(self):
        # we recover the saved url and commit from conandata.yml and use them to get sources
        git = Git(self)
        sources = self.conan_data["sources"]
        git.clone(url=sources["url"], target=".")
        git.checkout(commit=sources["commit"])

    def build(self):
        # build() will have access to the sources, obtained with the clone in source()
        cmake = os.path.join(self.source_folder, "CMakeLists.txt")
        hello = os.path.join(self.source_folder, "src/hello.cpp")
        self.output.info("MYCMAKE-BUILD: {}".format(load(self, cmake)))
        self.output.info("MYFILE-BUILD: {}".format(load(self, hello)))

This conanfile does:

  • In the export() method, it captures the url and commit, according to the rules of get_url_and_commit() above

  • The url and commit are saved in the conandata.yml

  • These two first steps happen in the conan export or first part of conan create when the recipe is exported to the cache.

  • When the recipe is building from sources in the cache, it will call the source() method which will clone and checkout from the user folder if the commit is only local or from the git remote if the commit is remote too.

This conan create flow is not recommended for continuous usage. To develop and test, users should use the local flow (conan install + build system). Only in the last stage, to check that things are looking good to push, the user can do a local commit, and before pushing, do a conan create to check locally.