how your filenames could possibly require unicode support.
Simple. Assume a Windows XP user who chose user name like "／人◕‿‿◕人＼". Windows creates his Application data folder with that string as part of the path. Non-Unicode applications fail.
I tested it and proved it.
Of course that user is an idiot noob, but still.

the following code compiles fine and displays correctly:
Do you realize your example is invalid because it uses Lazarus? Lazarus includes tons of hacks and custom RTL patching to make UTF-8 work on Windows as if it was default.
I write in pure FPC. The FPC RTL doesn't have the Lazarus hacks. If I try accessing TFileStream.Create('c:\Users\／人◕‿‿◕人＼\Application Data\chentrah\chentrah.ini', fmOpenRead); it will fail even with the file in place.
Fpc 3.x does have much better support for Unicode paths and only requires minor patching. sadly, it is not ready yet.


you do realize the people who maintain Debian are entirely unrelated to the developers of FPC/Lazarus
I do indeed. The Debian maintainers are much more thorough in their approach to stability and they deem fpc 3.x not ready. I agree with them.