Building Chromium for Slackware

I thought it would be helpful, and in any case insightful, to describe how I build the Chromium (also -ungoogled) packages for Slackware.

It is not a trivial task but a necessary one I believe. Slackware users should have a choice of browsers – some prefer Mozilla Firefox, others Google Chrome, and then there’s LibreWolf and Chromium that are built on the same code base as respectively Firefox and Chrome. There are others too, but I decided to stick with packages for Librewolf  and Chromium (-ungoogled). This article will focus on Chromium because Librewolf is pretty trivial to compile into a package.

Google develops the Chromium source code using tools which it partly created and maintains itself and for another part extends and patches them from the originals. Most notorious are the heavily customized Clang and Rust compilers used inside Google. The Chromium code reflects those compiler customizations because its codebase contains sections that will fail to compile using the official releases from the LLVM Project and the Rust Team (on which Slackware bases its own llvm and rust packages).

Google formally stopped supporting 32bit releases for their binary distribution of Chrome as long ago as 2015 (that’s ten years ago!) but indicated that the Chromium source code would still be compilable on 32bit platforms. Over time it became clear that internal code reviews and checks only happen on 64bit OS-es and the 32bit compatibility has been susceptible to “code-rot” ever since. As evidenced in my SlackBuild script where more and more patches and code modifications have been added to keep the ability to compile Chromium sourcecode into 32bit binaries.

Google provides binary snapshots of their internally used versions of Clang and Rust which reduces the need for patches a lot. Unfortunately Google at some point in time stopped providing 32bit binaries and so these binaries are nowadays only provided for 64bit machine architectures. In the past I relied on these binary snapshots to compile Chromium for Slackware.
After Google stopped providing those 32bit binaries, I have been putting a lot of effort in making Chromium compilable using the Slackware stock Clang and Rust compilers.

Note: I compile Chromium and Chromium-ungoogled on Slackware 15.0 and make these packages available in repositories for both Slackware 15.0 and -current. The challenge with Slackware 15 is that the provided llvm and rust compiler packages are way too old to be able to compile Chromium. Therefore Patrick Volkerding provides newer llvm and rust packages in the ‘extra’ section of the Slackware 15.0 repository. From time to time I run into new issues with clang and upon request, Patrick then builds and uploads a newer version of llvm into the repository.

Let’s have a look at the required updates for a Slackware 15.0 system (Slackware-current is up-to-date on all these package versions):

• nodejs >= 20.13.0
• llvm >= 21
• rust >= 1.88.0
• nasm >= 2.14
• cmake >= 3.30.1

Some of these updates for Slackware 15.0 are in my own package repository (cmake, nodejs, nasm), some others in the ‘extra’ section of the official Slackware 15.0 package tree (llvm and rust).

When these updates are applied to Slackware 15, or in case you are running Slackware-current, compiling a Chromium package is simply:

# ./chromium.SlackBuild

… and compiling Chromium-ungoogled needs this commandline:

# USE_UNGOOGLED=1 ./chromium.SlackBuild

Note: you will need an enormous amount of RAM and lots of free disk space (in the filesystem which $TMP is pointing to) to run this build successfully, and then a lot of patience for that build to complete (my QEMU virtual machine needs about 12 hours to complete this build – per package).

From time to time, usually when the major version number of Chromium makes a jump, the source code has been modified to such an extent that the Slackware compilers will fail to build the binaries successfully. In that case (and if you are creating a 64bit package) you can force the SlackBuild to download and use Google’s binary clang and rust compiler snapshots using this commandline:

# BUILD_CLANG=1 ./chromium.SlackBuild

# BUILD_CLANG=1 USE_UNGOOGLED=1 ./chromium.SlackBuild

Usually this way the compilation will be successful.

Attribution:
Next to the Arch Linux PKGBUILD maintainer for Chromium, I depend more and more on the unparalleled knowledge of the NixOS package maintainers, to find the proper patches for my SlackBuild.
I would have been forced to drop the 32bit package support a long time ago if it were not for emilylange and networkException (NixOS) and Christian Heusel and Evangelos Foutras (Arch Linux).

I hope this article gave some insight into the life of a package maintainer.

Cheers, Eric