I found the problem. It is env/LC_CTYPE variable.

My locale is set to tr_TR.UTF-8
For now, clangd doesn't seem to like it.
Changing LC_CTYPE to en_US did the trick for me, on all ArchLinux installations...

I am not entirely familiar with clangd's behaviour (yet) but if it requires LC_CTYPE to be ASCII en_xx values, maybe TheIDE should ensure that it is.


Best regards,
Oblivion

GUI_APP_MAIN {
#ifdef PLATFORM_POSIX
SetEnv("LC_TYPE", "en_US.UTF8")
#endif