Reitse Eskens hits a weird error:
One of the transformations is to change one primary key column from integer to GUID. This is something you can do with some trickery you’ll see in the code. But what I found was that, even though the primary key is unique, the GUID’s weren’t. And then the fun starts digging into the why…
Read on for the research Reitse performed. I don’t even have a good guess for this, it’s so weird. It feels like a bug but it’s weird regardless.