Python’s Misc/gdbinit provides a helper to print the Python call stack. Because of some assumptions it makes, it won’t work for any thread except the main thread. This patch fixes that:

Index: gdbinit
===================================================================
--- gdbinit     (revision 53403)
+++ gdbinit     (working copy)
@@ -119,7 +119,7 @@

 # print the entire Python call stack
 define pystack
-    while $pc < Py_Main || $pc > Py_GetArgcArgv
+    while ($pc < Py_Main || $pc > Py_GetArgcArgv) && ($pc < t_bootstrap || $pc > thread_PyThread_start_new_thread)
         if $pc > PyEval_EvalFrame && $pc < PyEval_EvalCodeEx
            pyframe
         end

A similar change is required for pystackv.