docs/reference: Add note about multiple exceptions when heap is locked.
@@ -43,6 +43,11 @@ for the purpose. Debugging is simplified if the following code is included in an
import micropython
micropython.alloc_emergency_exception_buf(100)
+The emergency exception buffer can only hold one exception stack trace. This means that if a second exception is
+thrown during the handling of an exception while the heap is locked, that second exception's stack trace will
+replace the original one - even if the second exception is cleanly handled. This can lead to confusing exception
+messages if the buffer is later printed.
+
Simplicity
~~~~~~~~~~
