[gnome-builder] foundry: be tolerant of NULL error message

[Christian Hergert <chergert src gnome org>]

commit 0a317be41dfee269c17ade47961be978ab73bf56
Author: Christian Hergert <chergert redhat com>
Date:   Thu Apr 22 09:53:56 2021 -0700

    foundry: be tolerant of NULL error message

 src/libide/foundry/ide-build-manager.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/libide/foundry/ide-build-manager.c b/src/libide/foundry/ide-build-manager.c
index a1ca3b05a..0167bad2a 100644
--- a/src/libide/foundry/ide-build-manager.c
+++ b/src/libide/foundry/ide-build-manager.c
@@ -445,7 +445,8 @@ ide_build_manager_ensure_runtime_cb (GObject      *object,
 
   if (!_ide_runtime_manager_prepare_finish (runtime_manager, result, &error))
     {
-      g_message ("Failed to prepare runtime: %s", error->message);
+      if (error != NULL)
+        g_message ("Failed to prepare runtime: %s", error->message);
       IDE_GOTO (failure);
     }