Thanks for your help. I think with that fail log, and some confirmation, and the other inputs, I'll be able to debug it (and given more info about which versions fail, I might be able to even replicate). Don't feel like you have to do more in-depth; you've helped plenty already.

Since this is mostly my coffee-break and waiting-for-long-data-processess-to-finish keep-my-mind-active project, there can be long gaps between when I have time to work on it. Hopefully, I'll be able to get one or more failing installations tomorrow.