Could I get a login on the buildbot to make a fix?

I bet the problem is with the stdscr object.  PyCurses_InitScr()
does 'return (PyObject *)PyCursesWindow_New(stdscr);'.

PyCursesWindow_Dealloc() does:
  if (wo->win != stdscr) delwin(wo->win);

I bet FreeBSD is clearing contents of the stdscr global variable.  The condition in PyCursesWindow_Dealloc() is then true, and it tries to delwin() the old value, which is in wo->win.

One fix might be to keep a reference to that PyCursesWindow object holding stdscr, and change dealloc to 'if (wo != saved_stdscr_object)'.  Or maybe, since multiple calls to initscr() will create multiple window objects holding the value of stdscr, window objects should have a 'do_not_delwin' flag.