I have run into this "system-level" versus "application-level" problem before. Maybe my OS's package manager installed foo-fred.tgz but then foo has its own ma

I have run into this "system-level" versus "application-level" problem before. Maybe my OS's package manager installed foo-fred.tgz but then foo has its own manager and it wants to install a different version of fred, but I have absolutely no idea who maintains it, besides it magically pulling stuff off the webtubes from God-knows-where. And how do I verify the integrity of those packages? It's a nightmare. I just plug my nose and dive in and hope that whenever things go really bad it won't be on a day when I'm busy.