Merge branch '0.28.x'

Cython/Compiler/ModuleNode.py

@@ -707,7 +707,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         code.putln('static PyObject *%s = NULL;' % env.module_cname)
         code.putln('static PyObject *%s;' % env.module_dict_cname)
         code.putln('static PyObject *%s;' % Naming.builtins_cname)
-        code.putln('static PyObject *%s;' % Naming.cython_runtime_cname)
+        code.putln('static PyObject *%s = NULL;' % Naming.cython_runtime_cname)
         code.putln('static PyObject *%s;' % Naming.empty_tuple)
         code.putln('static PyObject *%s;' % Naming.empty_bytes)
         code.putln('static PyObject *%s;' % Naming.empty_unicode)

Cython/Utility/Exceptions.c

@@ -617,6 +617,12 @@ static int __Pyx_CLineForTraceback(PyThreadState *tstate, int c_line) {
 #if CYTHON_COMPILING_IN_CPYTHON
     PyObject **cython_runtime_dict;
 #endif
+
+    if (unlikely(!${cython_runtime_cname})) {
+        // Very early error where the runtime module is not set up yet.
+        return c_line;
+    }
+
     __Pyx_ErrFetchInState(tstate, &ptype, &pvalue, &ptraceback);
 
 #if CYTHON_COMPILING_IN_CPYTHON