Database migration from 9-4-stable to 9-5-stable (ce from source) aborts with segmentation fault

Database migration from 9-4-stable to 9-5-stable (ce from source) fails with segmentation fault. Eventually I want to upgrade from 9-5-stable to 10.0.0 then to 10.8.7, to 11.0.0, to 11-last finally to 12-latest.

The gitlab version is upgrade over the years from 6.8-stable…7-6-stable (following in between stable releases), then to 7-14-stable, to 8-0-stable…8-17-stable (following in between stable releases), 9-0-stable…9-4-stable. Upto and including 9-4-stable did not show any problem when running: ‘bundle exec rake db:migrate RAILS_ENV=production’. The database backend used is mariadb/mysql.

The system in question is running Fedora 31. Right from the start the rake tasks to migrate the database aborts with a segmentation fault. A snippit from the output:

"/home/git/gitlab/vendor/bundle/ruby/2.6.0/gems/activesupport-4.2.8/lib/active_support/core_ext/object/duplicable.rb:111: warning: is deprecated; use BigDecimal() method instead.
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
/home/git/gitlab/vendor/bundle/ruby/2.6.0/gems/activesupport-4.2.8/lib/active_support/dependencies.rb:408: [BUG] Segmentation fault at 0x00000000011af10c
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-linux]
Each run it crashes in different places, so it is likely a memory corruption that causes the segmentation fault. At the sametime it is difficult to pin-point the cause for this behaviour.

Before being able to start migrating the database from 9-4-stable to 9-5-stable I needed to update various gems and checked for a ruby interpreter error. I fail to find a solution from checking gitlab bugreports, google sources.

rake --version 12.0.0
bundle --version 1.17.2
ruby --version 2.6.5p114 (2019-10-01 revision 67812)

Did someone also ran into this issue?
Does someone has a clue where to start looking further?
Does someone has a solution?