10.x (Most recently 10.6.1) installation from source issues / Alpine Linux

Summary

Unable to install from source code Gitlab FOSS or EE on alpine in any 12.x series

Steps to reproduce

Follow Gitlab Installation from Source guide and encounter failures.

What is the current bug behavior?

During the bundle install --jobs $CPU_COUNT --deployment --verbose --without development test mysql aws the following fails on Alpine 3.11 (and earlier):

• Fails when attempting to find gemnasium service:

Fetching gem metadata from https://rubygems.org/........
Could not find gemnasium-gitlab-service-0.2.6 in any of the sources

• Dependency on charlock_holmes 0.75 does not compile. Later versions will compile, however there are dependent modules on 0.75

What is the expected correct behavior?

Succesful installation of modules allowing to proceed with regular installation from source instructions.

Can provide Dockerfile to show results/reproduce.