I think marc reffered to this
http://www.lazarus.freepascal.org/index.php/topic,9072.msg44958.html#msg44958Anyway the point is, Lazarus needs certain libraries, certain include files, headers, and what else => they must be installed one your linux system, or lazarus can not run.
These dependencies are not part of lazarus, they are part off other packages (X11, gtk, libc, gcc, ...).
Even if we wanted Lazarus could not simply include a copy of them, because they come in different versions, and vary for each system.
If Lazarus had it's own "installer", then this installer would still have to find all those dependencies (or even if it carried a 100 diff copies of them, it would have to find out which one to use).
And the best info to find out where or what they are is the package system.
It would be impossible, impracticable, and nonsensical for Lazarus to maintain it's own list, and try to be better at this than the official package system...
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The best way, do minimize issues, is at the time you install your Linux:
Somewhere there usually is an option, that let's you choose to install all the developer packages => then and only then all the stuff Lazarus needs, should be there already.