Here’s the error:
[2026-02-17T16:51:13.376629 #1] INFO -- : > cd /var/www/discourse && su discourse -c 'bundle install --jobs $(($(nproc) - 1)) --retry 3'
Your Ruby version is 3.3.8, but your Gemfile specified ~> 3.4
Do you have discourse Docker pinned to an old version? Or, it could be a bug, but it seems in) unlikely that such a bug would pass the build test.