@@ -147,7 +147,14 @@ class BlockingRunner(BaseRunner):

                                           return_when=first_completed)

                 for fut in done:

                     x = xs.pop(fut)

-                    y = fut.result()

+                    try:

+                        y = fut.result()

+                    except Exception as e:

+                        raise RuntimeError(

+                            'An error occured while evaluating '

+                            f'"{self.learner.function.__name__}({x})". '

+                            'See the top traceback for details.'

+                        ) from e

                     if do_log:

                         self.log.append(('add_point', x, y))

                     self.learner.add_point(x, y)

@@ -334,7 +341,14 @@ class AsyncRunner(BaseRunner):

                                              loop=self.ioloop)

                 for fut in done:

                     x = xs.pop(fut)

-                    y = fut.result()

+                    try:

+                        y = fut.result()

+                    except Exception as e:

+                        raise RuntimeError(

+                            'An error occured while evaluating '

+                            f'"{self.learner.function.__name__}({x})". '

+                            'See the top traceback for details.'

+                        ) from e

                     if do_log:

                         self.log.append(('add_point', x, y))

                     self.learner.add_point(x, y)