Just a quick follow-up to my previous post. It was somehow trickier than I thought to set arguments for CTest from CMake. In the end, the solution is quite simple, but existing resources weren’t as helpful as they should. For reference: If you type $ ninja test or $ make test in the generated build directory from CMake, CTest is invoked under the hood. By setting CMAKE_CTEST_ARGUMENTS at the right place in your Read more…
Hey you all, it’s been a while. Happy new year! In today’s blog post, I’d like to present you the solution for a problem I encountered. It’s not rocket science, but I didn’t find something helpful on the internet, and I love to make things easily googleable. TL;DR: Check out my example project on GitHub. I was working on a CMake-based project that builds libraries, which should be tested. These unit tests are Read more…
The other day, I was about to add an attribute to pkgs.lib using a nixpkgs overlay. There is a small and subtle pitfall when doing so, which made me create this short blog post. A basic overlay looks like this: By looking at the architecture diagram, we see that both prev and final refer to what pkgs is, just in different “generations” (or iteration steps) in the evaluation of the final nixpkgs instance. Read more…
Update: Since Cloud Hypervisor release v38, you can also run a Linux with this driver in Cloud Hypervisor and see the output. In earlier blog posts, I discussed QEMU’s debugcon device and presented a minimal driver for it written in x86 assembly. In this blog post, we go a little further and write a driver for Linux in C. The driver should provide a /dev/debugcon character device so that processes can open the Read more…
Update 2024-04-10: Updated with my latest knowledge about this topic. In this blog post, I’m going to show you briefly how you can compile an out-of-tree Linux kernel module in Nix. I use regular Nix for that and no Nix flakes. However, with flakes, the approach is similar. Background Knowledge An out-of-tree Linux kernel module is a standalone piece of code outside the Linux kernel source repository. They are used when people don’t Read more…
In this blog post, I explain how to test a single NixOS module in CI. By single NixOS module, I mean a module that provides some options and configurations, but itself is not a valid NixOS configuration. The use case is to have a common module (in a git repository) that you want to integrate in a full NixOS configuration, when you don’t have or want the full NixOS configuration at the same Read more…