My guess is that is has something to do with the LVGL version. I tried using 9.0.0 and had other errors, so downgraded to 8.3.11, as set in SquareLine.
LVGL9 shouldn’t be used yet because it has a changed API. So you’re at a good path by switching back to 8.3 branch of LVGL. From your error log it seems your Arduino build still wants to get a source (lv_windows.c) which is only present in LVGL9 and not in LVGL8 (where drivers are still at a different external ‘lv_drivers’ folder).
Arduino IDE does a lot of things in the background that you can’t see but hopefully it helps if you completely exit Arduino IDE, and start from a totally new export, this time selecting LVGL 8.3 everywhere where asked, and hopefully this way there won’t be residuals of LVGL9 build-scripts/configs.
Btw there are more Sunton-specific board-templates spread around here at the forum made by other users, I think you should try them if they’re better suited than the general-purpose Arduino TFT_eSPI board-template currently available in SquareLine Studio, kgschlosser’s is what first comes into my mind:
I have a similar issue for SquareLine studio 1.4.0. I am using Arduino IDE 2.3.2 and after updating to the latest SquareLine, export UI completely deletes all my other files in the same folder. So i had to move the UI files to a “UI” folder, but then Arduino IDE won’t compile:
fatal error: lv_i18n.h: No such file or directory #include “lv_i18n.h”
^~~~~~~~~~~
compilation terminated.
exit status 1
Compilation error: lv_i18n.h: No such file or directory
i18n library header is included when you enable ‘To be translated’ checkbox on at least one text in SquareLine Studio. But you need to add the i18n manually if you want to use it, there’s no automation for this at the moment. The compilation simply lacks that library.