I'm currently in the process of building newer snapshot images for Zyxel Armor Z2 (ipq806x) with the packages I want. However, during "Installing package" phase where the script downloads and installs the packages I specified, at some point the script would abort with a segfault. This never happened before and back then I was able to successfully build images from ImageBuilder.
The point when the segfault occurs is not random. It seems the ImageBuilder would segfault after installing some packages with a certain amount of size in total. Not sure how to debug this issue.