The project aims to build on a wide variety of Linux operating systems and compilers, but when it comes to producing portable builds, we use EL containers based on the manylinux project. This gives us the ability to produce binaries with wide compatibility by default to facilitate tarball distribution and embedding into other packages.
The CI uses a custom built therock_build_manylinux_x86_64. See the dockerfiles/build_manylinux_x86_64.Dockerfile. It is automatically rebuilt on pushes to main. For testing, changes can be pushed to a stage/docker/BRANCH_NAME branch, which will automatically result in a corresponding container rebuilt with stage-BRANCH_NAME tag in the package registry. See the dockerfile for instructions to build locally.