To install Lazarus (and FPC -- the underlying compiler) on Raspberry Pi in a simplest way, I would recommend to just install packages fpc and lazarus-ide on Raspberry Pi.

From command-line, as root:

Code:
apt install fpc lazarus-ide
Or use package manager (like Synaptic) to install these packages with a GUI. As of Raspbian 11 (based on Debian bullseye), this gives FPC 3.2.0 and Lazarus 2.0.10. Not the very latest FPC/Lazarus versions, but workable, and the installation process is easiest possible. And they will get updated with new Raspbian

Alternative 1: I would say the next-best alternative is to use fpcupdeluxe, https://castle-engine.io/fpcupdeluxe . Get it from https://github.com/LongDirtyAnimAlf/...eleases/latest , for 32-bit Raspberry Pi you want fpcupdeluxe-arm-linux. It allows to install various FPC/Lazarus versions, it will give you the latest FPC and Lazarus (3.2.2 and 2.2.2) without much effort. You may still want to do "apt install fpc" before using fpcupdeluxe -- this way fpcupdeluxe will have a starting compiler to bootstrap the latest FPC version.

Alternative 2: If you feel comfortable with shell, you may want to try a script like my https://github.com/castle-engine/cge...ll_fpc_lazarus . But admittedly this requires to understand a bit what's going on under the hood, it's a useful script for me (it's like "fpcupdeluxe but really really minimal, just do minimum steps to automatically install FPC/Lazarus from GitLab").

Shameless self-plug:

If you're doing games on Raspberry Pi, you may also want to take a look at my Castle Game Engine, https://castle-engine.io/ . We have recently released a big update with version 7.0-alpha.2. The engine features a comfortable visual editor and can be used with FPC (using Lazarus is optional; you need FPC + any text editor capable of editing Pascal files).

And we support Raspberry Pi, since a long time, because I love Raspberry Pi It's an amazing device, fully functional computer with amazing price and size. See my initial excited news about Raspberry Pi from 2019 and 2020. Our download page contains ready downloads for Raspberry Pi (32-bit -- just because that seems to be the default, for now, used by most people; I see it is also what you chose). All our releases are automatically done (by Jenkins) also for Raspberry Pi, the download linked above will give you a working game engine for Raspberry Pi with all the latest features described in "7.0-alpha.2" release notes

If this sparks an interest and you have any questions about Castle Game Engine, let me know!