RAILS_ENV=production script/about

sh: darcs: command not found
sh: hg: command not found
sh: bzr: command not found
sh: git: command not found
Environment:
  Redmine version                2.5.0.stable
  Ruby version                   1.9.3-p484 (2013-11-22) [x86_64-linux]
  Rails version                  3.2.17
  Environment                    production
  Database adapter               Mysql2
SCM:
  Subversion                     1.6.11
  Filesystem
Redmine plugins:
  no plugin installed