Redmine

The problem is if developers (role developers) want to create an internal issue (i.e. some implementation problems)
and this issue should not be visible to testers (role testers) which are creating issues viewable for everyone (i.e
application hang up, etc)

So the basic solution is to add list with roles in role permision tab:
"Can view issues created by:" [roles list]

Then tasters could only view issues created by themselves and developers could view issues created by developers and
by testers.

Other solution is to simple add ticker "Internal" in creating new issues tab, and then other ticker "View
internal issues" in role permission tab.