Build current FPC and Lazarus for Raspberry Pi OS

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Raspberry Pi OS Bullseye (based on Debian 11 Bullseye) has FPC and Lazarus available in the repositories, but they suffer from the same "design decisions" that don't allow for a nice experience, namely the smooth IDE rebuilding capability based on source packages that is possible with FPC/Lazarus official .deb packages vs the crippled experience with the official Debian/Raspberry Pi OS packages. One wishes there were official FPC/Lazarus packages for Raspberry Pi OS as there are for Intel Debian/Ubuntu, which are also frequently updated; not being that the case (at least for now), this page shows the steps for building your own FPC, FPC-source and Lazarus packages for Raspberry Pi OS. Example shows steps for Lazarus 2.2.0 which includes FPC 3.2.2, most recent at the time of writing. Adjust accordingly.


  • Raspberry Pi 4 Model B, 4 GB (less memory models would require swap), with appropriate cooling (author uses aluminum case that doubles as heatsink) to avoid throttling due to excessive heat. Raspberry Pi 400 works too.
  • Latest Raspberry Pi OS Bullseye fully updated


  1. Install subversion: sudo apt install subversion
  2. Install Free Pascal compiler: sudo apt install fp-compiler
  3. Test if all ok: fpc abcd. This invokes the just installed compiler trying to compile a non-existent file (abcd). A multiline message will be shown including the compiler version.
  4. Non-step note: the following steps are mostly based on this
  5. Install development libraries: sudo apt install libgtk2.0-dev libgpm-dev libncurses-dev
  6. mkdir ~/pascal
  7. cd ~/pascal
  8. svn checkout fpc, you have to be online for this and the next step to work.
  9. git clone
  10. cd lazarus
  11. git checkout lazarus_2_2_0
  12. cd tools/install
  13. Edit, look for line with the following content: arm) ppcbin=arm; FPCArch=arm;;, (currently line 109). Copy and paste this line below itself, so it will appear twice. Edit this copy to read like this: armhf) ppcbin=arm; FPCArch=arm;;. Now save the changes and exit.
  14. Run the script: ./ fpc ~/pascal/fpc/. This will compile the latest compiler using the compiler included with Bullseye. It takes about 11 minutes. A .deb file will be created: fpc-laz_3.2.2-yymmdd_armhf.deb; the exact name will be shown at the end of the compilation.
  15. Uninstall Free Pascal compiler: sudo apt purge fp-compiler && sudo apt --purge autoremove
  16. Install the just created FPC Debian package: sudo dpkg -i ~/pascal/lazarus/tools/install/fpc-laz_3.2.2-yymmdd_armhf.deb && sudo apt install -f. Check if it works: fpc abcd should show the newly installed FPC compiler.
  17. cd ~/pascal/lazarus/tools/install
  18. ./ fpc-src ~/pascal/fpc/. This builds the FPC source package in about 3 minutes: fpc-src_3.2.2-yymmdd_armhf.deb.
  19. Edit, look for line with the following content: echo "$Arch is not supported.", (currently line 86). Copy the 3 lines above it and paste them just below themselves: at this time it is copy lines 83 to 85 and paste them between lines 85 and 86. In the just pasted lines (lines 86-88), replace sparc with armhf, and ppcsparc with ppcarm. Look for the first fi just below; copy and paste it below itself (copy line 91 below itself, so line 91 and 92 read the same). For you coders out there, you are adding another if to a nested if, with its corresponding fi. Now save and exit.
  20. ./ This will build the Lazarus IDE Debian package lazarus-project_2.2.0-0_armhf.deb. It will take about 15 minutes.
  21. Install the FPC source and Lazarus packages: sudo dpkg -i fpc-src_3.2.2-yymmdd_armhf.deb lazarus-project_2.2.0-0_armhf.deb && sudo apt install -f
  22. Save *.deb to another location, to reinstall later if needed or to share with friends: remember this is free software. Mine are here: (here you will also find 64-bit packages for the recently released Raspberry Pi OS 64-bit, with copies of the two files modified in this article, with 64-bit edits).
  23. cd && rm -rf ~/pascal ~/tmp
  24. Edit as root /etc/fpc.cfg. Search for gcclib. In the line below, replace cpuaarch64 with cpuarm. This removes error about missing crtbegin.o when building apps.
  25. Change the debugger backend to gdb: Tools/Options/Debugger backend.

You can now finally enjoy your fully working, fully up to date Lazarus. Find it in the Programming section of the Raspberry menu. Now try to install a package, for example lazreport; it will work!

DISCLAIMER: these are UNOFFICIAL packages created from modified official sources. DO NOT ASK FOR SUPPORT ANYWHERE, neither on the forums or with the author of this article; use at your own risk.