Description
The ctan target still copies files twice, as far as I can tell. There was a commit to address this, but it got reversed - possibly because somebody complained the fix much worse than the bug 😉 .
I'm adding this because I assume this has got forgotten and I'd forgotten about it, too.
This is what I remember of that discussion:
The basic problem I have is that l3build wants to build a non-compliant archive and I need to persuade it to build a compliant one. Right now, I copy a key function and wrap it. Then I change the value of the variables which determine what gets packed. If I don't change the variables, l3build adds new copies of files I've moved into the correct places.
But the fix removed the first copy rather than the second, which made it impossible to have the files copied and move them into the right place without rewriting the entire function, rather than just wrapping it. Removing the second, on the other hand, wouldn't work for bundles (possibly?). A hook in the right place would make it possible to move files copied at the right place to work for bundles. So, there was going to be a hook ... (or hooks, maybe? I think there was another use-case, too. @davidcarlisle, possibly?)
[I know this is confused. A less confused discussion is on TeX SE somewhere .... This is just a postit note ....]