[add] toki-debug class to assist in debugging bitbake issues

classes/toki-debug.bbclass

+# This code is adapted from the Python Cookbook section "Getting More Information from Tracebacks" by Bryn Keller
+# https://www.oreilly.com/library/view/python-cookbook/0596001673/ch14s05.html
+
+def debug_yocto(d)
+    import inspect
+    import traceback
+
+    tb = traceback.extract_stack()
+    bb.warn('\n'.join(traceback.format_list(tb)))
+
+    bb.warn("Locals by frame, innermost last")
+    stack = inspect.stack()
+    for frameinfo in stack:
+        frame = frameinfo.frame
+        bb.warn("")
+        bb.warn("Frame %s in %s at line %s" % (frame.f_code.co_name,
+                                               frame.f_code.co_filename,
+                                               frame.f_lineno))
+        for key, value in frame.f_locals.items():
+            # We have to be VERY careful not to cause a new error in our error
+            # printer! Calling str() on an unknown object could cause an
+            # error we don't want, so we must use try/except to catch it --
+            # we can't stop it from happening, but we can and should
+            # stop it from propagating if it does happen!
+            try:
+                bb.warn("\t%20s = %s" % (key, str(value)))
+            except:
+                bb.warn("\t%20s = <ERROR WHILE PRINTING VALUE>" % key,)