Thanks for resolving. And especially for adding the empty line to ubiboot.log! (makes it way easier to read )
Another suggestion/question from my side: you have modified the G_global vars to be named according to the OS slot (and not anymore names). BUT the symlinks in /mnt are still named according to the OS names (e.g. G_OS1_NAME="Nitdroid", but G_OS1_1_FILE="/boot/Nitdroid/boot/zImage.pr13")? As you compiled all into the kernel and did not put the ubifs.tar online, I cannot see the available symlinks. Or are they created on the fly (according to G_OS1_NAME)? Would you please be so kind and give more info here? Or put sources online?