print traceback on failed import (#537)

include/pybind11/common.h

@@ -511,7 +511,6 @@ PYBIND11_RUNTIME_EXCEPTION(stop_iteration, PyExc_StopIteration)
 PYBIND11_RUNTIME_EXCEPTION(index_error, PyExc_IndexError)
 PYBIND11_RUNTIME_EXCEPTION(index_error, PyExc_IndexError)
 PYBIND11_RUNTIME_EXCEPTION(key_error, PyExc_KeyError)
 PYBIND11_RUNTIME_EXCEPTION(key_error, PyExc_KeyError)
 PYBIND11_RUNTIME_EXCEPTION(value_error, PyExc_ValueError)
 PYBIND11_RUNTIME_EXCEPTION(value_error, PyExc_ValueError)
-PYBIND11_RUNTIME_EXCEPTION(import_error, PyExc_ImportError)
 PYBIND11_RUNTIME_EXCEPTION(type_error, PyExc_TypeError)
 PYBIND11_RUNTIME_EXCEPTION(type_error, PyExc_TypeError)
 PYBIND11_RUNTIME_EXCEPTION(cast_error, PyExc_RuntimeError) /// Thrown when pybind11::cast or handle::call fail due to a type casting error
 PYBIND11_RUNTIME_EXCEPTION(cast_error, PyExc_RuntimeError) /// Thrown when pybind11::cast or handle::call fail due to a type casting error
 PYBIND11_RUNTIME_EXCEPTION(reference_cast_error, PyExc_RuntimeError) /// Used internally
 PYBIND11_RUNTIME_EXCEPTION(reference_cast_error, PyExc_RuntimeError) /// Used internally

include/pybind11/pybind11.h

@@ -580,7 +580,7 @@ public:
     static module import(const char *name) {
     static module import(const char *name) {
         PyObject *obj = PyImport_ImportModule(name);
         PyObject *obj = PyImport_ImportModule(name);
         if (!obj)
         if (!obj)
-            throw import_error("Module \"" + std::string(name) + "\" not found!");
+            throw error_already_set();
         return reinterpret_steal<module>(obj);
         return reinterpret_steal<module>(obj);
     }
     }
 
 
@@ -1495,7 +1495,7 @@ PYBIND11_NOINLINE inline void print(tuple args, dict kwargs) {
     } else {
     } else {
         try {
         try {
             file = module::import("sys").attr("stdout");
             file = module::import("sys").attr("stdout");
-        } catch (const import_error &) {
+        } catch (const error_already_set &) {
             /* If print() is called from code that is executed as
             /* If print() is called from code that is executed as
                part of garbage collection during interpreter shutdown,
                part of garbage collection during interpreter shutdown,
                importing 'sys' can fail. Give up rather than crashing the
                importing 'sys' can fail. Give up rather than crashing the