I don't have a working Lazarus on my Ubuntu at the moment, but once it used to... i brokes it
Have you tried simply from Synaptic packet handler? You can set it to list external sources or something if fpc doesn't list by default.
What i guess should be done is a perfect clean up first.
Also the way some people install it, is extracting them in your /home/ or something manually. That way the files are all in 1 place like in Windows and you may have easier time with it. Ubuntu is using so many different folders in the system that it makes head hurt.
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