On Tue, Oct 17, 2017 at 12:31 PM Berry, Charles <address@hidden
The copy buffer that org-export-as sets up will contain this src block *after* the babel process runs.
As you can see the headers are stripped off of it.
Oh! That explains!
So you need to do something tricky to hold onto those headers. I do not know of a seamless way to do this. FWIW, this is handled in ox-ravel by hacking babel so it produces #+ATTR_ lines just before the src block result in the copy buffer. Those lines hold the header info which the ravel exporter trancoders can consult.
I like that approach. I found your ox-ravel project on GitHub and have tangled it to ox-ravel.el.
It would be great if you an paste the revelant snippets of code here as that library is ~800 lines.
I still hope there is some way to prevent doing this hack, or if a non-intrusive change in Org code can still have the :parameters available during export. Would it be possible to remove *only* babel-recognized parameters and leave the unidentified parameters (which could be specific to an exporter) intact?