My suggestion is to explicitly output "FQBN is missing" which is done when you launch the arduino-cli. ... Neovim v11 with nvim-lspconfig Setup arduino-language-server with Neovim. Setup demo project: ...

A compact Arduino-based system that reads ambient light levels using an LDR sensor, displays the measured illuminance (in lux) on a 16×2 LCD, and provides a color-coded visual indicator via an RGB LED ...