Added message to EOFError.
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index 1f1dcae..db9a088 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -342,7 +342,8 @@
 			}
 			if (n < 0 && buf == BUF(v)) {
 				DECREF(v);
-				err_set(EOFError);
+				err_setstr(EOFError,
+					   "EOF when reading a line");
 				return NULL;
 			}
 			break;