The build of the docker image returns the following error: CXXLD clientnb CXXLD connect CXXLD lokitclient CXXLD loolmap sudo /sbin/setcap cap_fowner,cap_mknod,cap_sys_chroot=ep loolforkit sudo: sorry, you must have a tty to run sudo Makefile:3276: recipe for target 'all-local' failed I think the error is cause by the change of the user in the dockerfile, since user is not root anymore.
There are regular docker builds, so the procedure still works. What steps are you following?
The build is broken: https://ci.libreoffice.org/job/lo_online_docker_master
That was an issue on the builder, should work now (build fails at another place currently).