Bazel vs Conan: What are the differences?

Introduction:

In the world of software development, there are various build tools available to facilitate the building and packaging of code. Two popular build tools are Bazel and Conan. Bazel is an open-source build and test tool developed by Google, while Conan is an open-source package manager developed by JFrog. Although both tools serve the purpose of managing code dependencies, there are some key differences between them.

1. Build System vs Package Manager: The fundamental difference between Bazel and Conan lies in their primary focus. Bazel is primarily a build system, designed to provide a build infrastructure for large-scale projects. It excels in incremental and parallel builds, enabling faster and more efficient builds of complex software systems. On the other hand, Conan is primarily a package manager, specializing in managing and resolving dependencies for different programming languages. It simplifies the process of retrieving, building, and managing software libraries and components.

2. Language and Platform Support: Bazel and Conan differ in their supported programming languages and platforms. Bazel supports a wide range of programming languages, including C++, Java, Python, and more. It is platform-agnostic and can be used on Linux, macOS, and Windows. On the other hand, Conan supports a broader range of programming languages, including C++, Python, JavaScript, and others. It also supports multiple platforms, including Linux, macOS, Windows, and even embedded systems.

3. Dependency Management Approach: Bazel and Conan employ different approaches to manage dependencies. Bazel uses a declarative approach, where the dependencies are explicitly defined and managed within the build files. It ensures that all dependencies are built and linked correctly for the target code. On the other hand, Conan uses a more flexible and dynamic approach. It allows developers to define dependencies using a package manifest file, which can be easily shared and reused across projects. Conan also provides versioning and dependency resolution capabilities, ensuring the correct versions of libraries are used.

4. Build Caching: Bazel and Conan differ in their approach to build caching. Bazel has a powerful build caching mechanism that enables the reuse of previously built artifacts. It intelligently analyzes the dependencies and builds only the necessary parts, resulting in faster build times. However, Conan does not have built-in build caching capabilities. It focuses more on the caching and management of packages themselves, rather than the build artifacts.

5. Integration with Build Systems: Another key difference between Bazel and Conan lies in their integration with build systems. Bazel integrates seamlessly with popular build systems like Gradle and Maven, making it easier to incorporate Bazel into existing development workflows. It provides plugins and build tool-specific support to ensure smooth integration. In contrast, Conan does not directly integrate with build systems like Gradle or Maven. It operates as a separate package manager, and the integration with build systems needs to be manually set up.

6. Community and Ecosystem: Bazel and Conan have different levels of community support and ecosystem. Bazel has a strong and active community backed by Google, with extensive documentation, tutorials, and support available. It also has a large ecosystem of rules and extensions developed by the community, enhancing its capabilities. Conan, while having a growing community, may have a smaller ecosystem compared to Bazel. However, it offers integration with other package managers like CMake, making it easier to leverage existing packages.

In summary, Bazel is primarily a build system focused on large-scale projects with efficient build processes, while Conan is a package manager that simplifies dependency management across various programming languages and platforms. Bazel has a wider language support and better build caching capabilities, while Conan offers a more flexible dependency management approach and better integration with existing build systems. Both tools have their strengths and can be chosen based on the specific needs of the project.