How to Use the Command 'debuild' (with examples)

The debuild command is a powerful tool used by developers and maintainers to build Debian packages from source code. It is part of the devscripts package and streamlines the process of converting source code into a .deb package, which is the package format used by the Debian operating system and its derivatives. This command handles various configurations and checks to ensure that the package meets the Debian standards. Here, we’ll explore several use cases to demonstrate how debuild can be used effectively in different scenarios.

Use case 1: Build the Package in the Current Directory

Code:

debuild

Motivation:

The most straightforward use of debuild is to build a Debian package from the source code located in the current directory. This is useful for developers who have completed their coding and testing of a software application and now want to package their application for deployment on Debian-based systems. By running debuild without additional flags, you initiate a comprehensive build process that compiles the source code, runs any necessary tests, and prepares the package for distribution.

Explanation:

• debuild: This is the command to build a Debian package. When used alone, it considers the current directory as the working directory containing the source code and all necessary files for building the package. It executes several steps, including compiling the code and packaging it into a .deb file, while also running various checks to ensure compliance with Debian standards.

Example output:

Upon successful execution, you might see a series of messages indicating compilation progress, checks being performed, and eventually a successful build notification such as:

dpkg-deb: building package 'your-package' in '../your-package_1.0-1_amd64.deb'.

This implies that the package has been successfully built and is available in the parent directory.

Use case 2: Build a Binary Package Only

Code:

debuild -b

Motivation:

In some cases, you may only need the binary version of a package, as opposed to the source version. This is often the case when you are deploying software to a production environment or providing software to users who do not need access to or do not wish to modify the source code. Building only the binary package reduces the build time and the final package size, making it more efficient when source code is unnecessary.

Explanation:

• -b: This flag tells debuild to build only the binary version of the package. The tool skips the source packaging step and directly compiles the code to generate the binary files, which are then packaged into a .deb file.

Example output:

Similar to the standard build process, you’ll see output indicating progress. The final output may be something like:

Binary files built successfully; package is in '../your-package_1.0-1_amd64.deb'.

This output confirms that the binary package alone has been created.

Use case 3: Do Not Run Lintian After Building the Package

Code:

debuild --no-lintian

Motivation:

Lintian is a tool used to check Debian packages for common errors and policy violations. While it’s a great tool for ensuring package quality, there may be instances where you’re confident in the package’s quality, or you may be working in a time-constrained environment where you need to skip this step. This option is especially useful during the iterative stages of development, where frequent builds are necessary, and running lintian each time isn’t necessary.

Explanation:

• --no-lintian: This flag instructs debuild not to run the lintian tool after building the package. By skipping these checks, the package building process can be expedited, though it skips a critical quality assurance step.

Example output:

Without lintian checks, the build output will look similar to a regular build minus any lintian errors or validation messages. The build confirmation might be:

Package build completed! Skipped lintian checks.

This indicates a successful package build without running the lintian tool.

Conclusion:

The debuild command is a versatile tool essential for building Debian packages, offering several options to customize the build process according to requirements. Whether you need a complete package, only the binaries, or a quick build without the added checks, debuild caters to various needs, streamlining the deployment of software in Debian-based environments. Understanding these use cases can significantly enhance your efficiency and effectiveness as a software developer or Debian package maintainer.