ls_parse: improve debugging by printing a trace

In case parsing a linker script fails, generate a trace, so that
debugging is possible. This way, unknown blocks in linker scripts
can be spotted more easily.

Author: nmanthey

scripts/ls_parse.py

@@ -15,6 +15,7 @@
 import subprocess
 import sys
 import textwrap
+import traceback
 
 
 def epilog():
@@ -282,6 +283,7 @@ def close_brace_fun(state, _, buf):
         state["UNKNOWN"] = False
     else:
         error("Not in block\n%s", buf)
+        traceback.print_stack()
         exit(1)