How to capture package version from SCM: git¶
Git() helper from tools, can be used to capture data from the Git repo in which
the conanfile.py recipe resides, and use it to define the version of the Conan package.
from conans import ConanFile, tools def get_version(): git = tools.Git() try: return "%s_%s" % (git.get_branch(), git.get_revision()) except: return None class HelloConan(ConanFile): name = "Hello" version = get_version() def build(self): ...
In this example, the package created with conan create will be called
Hello/branch_commit@user/channel. Note that
if it is not able to get the Git data. This is necessary when the recipe is already in the
Conan cache, and the Git repository may not be there,. A value of
None makes Conan
get the version from the metadata.
How to capture package version from text or build files¶
It is common that a library version number would be already encoded in a text file, build scripts, etc. As an example, let’s assume we have the following library layout, and that we want to create a package from it:
conanfile.py CMakeLists.txt src hello.cpp ...
The CMakeLists.txt will have some variables to define the library version number. For simplicity, let’s also assume that it includes a line such as the following:
cmake_minimum_required(VERSION 2.8) set(MY_LIBRARY_VERSION 1.2.3) # This is the version we want add_library(hello src/hello.cpp)
Typically, our conanfile.py package recipe will include:
class HelloConan(ConanFile): name = "Hello" version = "1.2.3"
This usually requires very little maintenance, and when the CMakeLists version is bumped, so is the conanfile.py version. However, if you only want to have to update the CMakeLists.txt version, you can extract the version dynamically, using:
from conans import ConanFile from conans.tools import load import re def get_version(): try: content = load("CMakeLists.txt") version = re.search(b"set\(MY_LIBRARY_VERSION (.*)\)", content).group(1) return version.strip() except Exception as e: return None class HelloConan(ConanFile): name = "Hello" version = get_version()
Even if the CMakeLists.txt file is not exported to the local cache, it will still work, as the
get_version() function returns None
when it is not found, and then takes the version number from the package metadata (layout).