Argtype descriptions name a literal parameter's cost, a phase's error is the phase's report, the ^-code table's grave-accent and dieresis rows (from dev ee86ca467512)

mac/eval.h

@@ -36,3 +36,12 @@ public:
     Machine m_machine;
     Locator m_loc;
 };
+
+// The Python exception the last fetch saw (Eval_python::fetch_python_exception):
+// its type name and its str().  The Error that fetch produces carries the
+// whole traceback; a caller that wants the exception's OWN words for a
+// headline -- Machine::run_phase_functions, reporting a phase's ValueError
+// as the phase's message about the document -- reads these.  Declared here
+// so machine.cpp needs no Python header.  (TODO 77, 2026-10-13)
+std::string last_python_exception_type();
+std::string last_python_exception_text();