GitLab installation from sources on Ubuntu 18.04

I’m trying to install GitLab on Rock64 board running Armbian (ARMBIAN 5.45 user-built Ubuntu 18.04 LTS 4.4.132-rk3328)

In general, I’ve followed the installation guide (https://docs.gitlab.com/ee/install/installation.html) but all the dependencies were installed with apt from default repository (ie with just ‘apt install’), except yarn.

Finally I’ve stuck at https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/install/installation.md#initialize-database-and-activate-advanced-features
sudo -u git -H bundle exec rake gitlab:setup RAILS_ENV=production

It fails with error
Failed to connect to Gitaly…

I’ve also tried to do the same in the docker container (amd64) for bionic (running on bionic) and found the same issue.

What’s wrong? Should I precisely follow the installation guilde? It looks like those instructions are just to install up-to-date versions of dependencies, but bionic seems already have appropriate versions.
I have no experience with go/ruby/bundle/rake, so it’s hard to narrow down the search area.

Note: in my early experiments, I was able to find out an issue with compilation/linking of some component (two contrary options were included simultaneously: the option and its inversion). Unfortunately I did not write it down and cannot yet find it again now…