If I move the WT_SESSION_IMPL structure members around, this line of code:
Old value = 0 New value = 34382041616 at ../../../lang/python/wiredtiger_wrap.c:6346 warning: Source file is more recent than executable. 6346 ((WT_SESSION_IMPL *)(*arg5))->lang_private = pcb;
overwrites a random value in the session.
I thought it was a dependency problem, but I rebuilt wiredtiger_wrap.c from scratch, and that didn't fix it.