Install Qt6 in Arch Linux

first you need an sudo access, to install basic development package you need install following package

$ pacman -Ss qt6- | rg -i installed

extra/qt6-base 6.9.1-1 (qt6) [installed]
extra/qt6-declarative 6.9.1-1 (qt6) [installed]
extra/qt6-languageserver 6.9.1-1 (qt6) [installed]
extra/qt6-svg 6.9.1-1 (qt6) [installed]
extra/qt6-translations 6.9.1-1 (qt6) [installed]

• run sudo pacman -S qt6-base qt6-declarative qt6-languageserver qt6-svg qt6-translations --noconfirm
• wait until complete
• next, to check if qt6 installed, we will compile basic qt example
• run git clone https://github.com/qt/qtdoc.git
• then cd to qtdoc example coffe, cd qtdoc/examples/demos/coffee
• run cmake -S . -B build, you can change build to another name (its build output)
• build example with cmake --build build
• next you can run the example with ./build/coffeemachine
• if all working, you will see this

Setup LSP with Neovim (LazyVim config)

• next to setup lsp we need to check installed qmlls in our /usr/bin/qmlls6 (the name may difference based on version)
• you need change cmd argument from nvim-lspconfig based on your installed qmlls version inside init.lua

 File: init.lua

   1   │ -- bootstrap lazy.nvim, LazyVim and your plugins
   2   │ require("config.lazy")
   3 + │ 
   4 + │ vim.lsp.enable("qmlls")
   5 + │ vim.lsp.config("qmlls", {
   6 + │   cmd = { "qmlls6" },
   7 + │ })

• then hopefully lsp will work :)

Reference

• nvim-lspconfig qmlls