Gitlab source archive contains files from build directory
The CPack machinery for building the final source archive currently includes the full build tree when building on Gitlab.
This is due to the build directory being located under the initial (git) source directory.
The correct way to do this is by changing the source directory in Gitlab, but this is currently blocked by https://gitlab.com/gitlab-org/gitlab-runner/issues/4203
For now, the build directory needs to be removed manually from the packed archive, before packing it again.