Instead of using the debian package to install redmine install from subversion
https://www.redmine.org/projects/redmine/wiki/Download use 4.2.3
Using instructions here:
https://www.redmine.org/projects/redmine/wiki/redmineinstall
4.2 has support fully for ruby 2.7
Instead of using the debian package to install redmine install from subversion
https:/ /www.redmine. org/projects/ redmine/ wiki/Download use 4.2.3
Using instructions here:
https:/ /www.redmine. org/projects/ redmine/ wiki/redmineins tall
4.2 has support fully for ruby 2.7