<p></p>
<p>Thanks for digging in further and narrowing it down. I will analyze to see what is the reason, like the references to the buffers become invalid as the needs for defines/substdefs can exceed/overwrite them. It is interesting that it didn't surface for defines which had this kind of capability/behaviour for long time before, the commit referenced above extended for substdef to make it coherent, because this one makes a define behind.</p>

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