When you have Netrunner installed, and - if you want a rolling release (it's great) - enabled the 'Debian testing' repository in Synaptic - repositories - then I recommend that you install Lazarus / FPC from Debian instead of the 'official' ones from Lazarus.
The Debian testing ones are at version 1.6.2 / 3.0.0 - and then you don't have to worry about accidentally upgrading Lazarus/FPC to older versions (as will happen with the debs from Lazarus' Sourceforge files section).
Why? Because the Lazarus debs haven't been made to take Debian testing (or backports) into account - because that is essentially 'future'.
Edit:
Meta-packages fpc and lazarus should ensure that you receive updates - they currently point to 1.6.2 and 3.0.0.
Then, after having a working, globally installed, Lazarus installation, then you can jump into building your own, personal Lazarus/FPC installation using fpcupdeluxe.
Since you can have both installed at the same time - fpcupdeluxe is creating a self-contained installation - you should be able to at least have a global, working Lazarus, even if you have goofed the local fpcdeluxe installation.