I am no Linux expert but I seem to remember you need to be in ROOT or SUDO xxxx to install Lazarus etc.
Yeah, and that is exactly where the world is starting to tumble down.
Lazarus needs to rebuild itself when installing for example a new component, can't store the results in the write protected directory and circumvent that by storing the results in the configuration directory. (*)
So far, everything is alright and honky dory.
But then.. you decide to upgrade Lazarus or add another installation of Lazarus and the shit hits the fan because people seem to forget that either a) you need to clearly distinct between the two installed versions (--pcp) or b) make sure there are no remnants of another installation left.
Linux is like my wife, no sense of humor!
I wouldn't dare to comment on that but I do can tell you that you can bend the will(power) of Linux so that it starts listening to what you want. Just stay the h*ll away from those installation packages and package managers. It makes things overly complicated for nothing.
edit: * unless starting Lazarus with sudo/admin rights as well, which defeats the whole purpose of having a separated user account (with less privileges).