@Hartmut
Please make sure your Lazarus, FPC and FPC-src are installed correctly. If you have fpc-source installed, it means you're using the installation package provided from Ubuntu. If you manually install Lazarus (using the deb files from SourceForge), it should be
fpc-src.
I managed to combine Lazarus from SourceForge with FPC from Ubuntu repository but it didn't work.
You may need to do a clean installation, so use these below to do the full uninstallation first:
01. Uninstall lazarus, fpc, fpc-src
02. Delete ~/.lazarus, except: editoroptions, environmentoptions
03. Delete /etc/fppkg (folder)
04. Delete /etc/fp.*
05. Delete /usr/share/fpcsrc (folder)
06. Delete /usr/lib/fpc (folder)
07. Delete /usr/bin/ppc*Note:
I keep those 2 files in step #2 because I want to keep some setttings I configured for Lazarus. You can delete them if you want.
After performing the complete uninstallation you now can instal the Lazarus/FPC. You may need a computer reboot. I know it sounds silly

, but I have bad experience messing the installation, which causes I failed to install Lazarus/FPC no matter how hard I tried. I just shut down my pc, took a break wacthing tv, then came back to install, it worked effortlessly.
For installing Lazarus/FPC, you can follow the link I gave on the previous post.
After the Lazarus installed, you can test it by doing an IDE rebuild:
Lazarus main menu > Tools > Built Lazarus with Profile: Normal IDEIf you don't get any error when building the IDE, you now can continue to do the cross compiling using the steps I gave previously.