Try to debug PGI

include/pybind11/detail/type_caster_base.h

@@ -479,7 +479,7 @@ PYBIND11_NOINLINE std::string error_string(PyObject *type, PyObject *value, PyOb
     result += ": ";
 
     if (value) {
-        result += str(value).cast<std::string>();
+        result += (std::string) str(value);
     }
 
     if (trace) {
@@ -517,6 +517,9 @@ PYBIND11_NOINLINE std::string error_string() {
     error_scope scope; // Preserve error state.
     if (scope.type) {
         PyErr_NormalizeException(&scope.type, &scope.value, &scope.trace);
+        /*if (scope.trace != nullptr){
+            PyErr_SetTraceback(scope.value, scope.trace);
+        }*/
     }
     return error_string(scope.type, scope.value, scope.trace);
 }

include/pybind11/pytypes.h

@@ -12,6 +12,7 @@
 #include "detail/common.h"
 #include "buffer_info.h"
 
+#include <exception>
 #include <type_traits>
 #include <utility>
 
@@ -397,9 +398,15 @@ public:
     inline ~error_already_set() override;
 
     const char *what() const noexcept override {
-        if (m_lazy_what.empty() && m_type) {
+        if (m_lazy_what.empty()) {
             try {
                 m_lazy_what = detail::error_string(m_type.ptr(), m_value.ptr(), m_trace.ptr());
+            } catch (const std::exception &e) {
+                m_lazy_what
+                    = std::string(
+                          "Unknown internal error occurred while constructing error_string:")
+                      + e.what();
+                return m_lazy_what.c_str();
             } catch (...) {
                 m_lazy_what = "Unknown internal error occurred";
             }