gluon/package/gluon-legacy/luasrc/lib/gluon/upgrade/000-legacy

#!/usr/bin/lua

local site = require 'gluon.site_config'
local sysconfig = require 'gluon.sysconfig'

for _, file in ipairs(site.legacy.version_files) do
  if os.remove(file) then
    -- Set version being upgraded from to 'legacy'
    sysconfig.gluon_version = 'legacy'
  end
end