[gnome-builder/wip/gtk4-port] libide/foundry: allow NULL clean launcher

[Christian Hergert <chergert src gnome org>]

commit a38d639eda79f14a628d3d295ff20595ef16f882
Author: Christian Hergert <chergert redhat com>
Date:   Thu Jun 23 01:15:44 2022 -0700

    libide/foundry: allow NULL clean launcher

 src/libide/foundry/ide-pipeline-stage-launcher.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/libide/foundry/ide-pipeline-stage-launcher.c 
b/src/libide/foundry/ide-pipeline-stage-launcher.c
index de7eeea25..57d0ac4ed 100644
--- a/src/libide/foundry/ide-pipeline-stage-launcher.c
+++ b/src/libide/foundry/ide-pipeline-stage-launcher.c
@@ -589,7 +589,7 @@ ide_pipeline_stage_launcher_set_clean_launcher (IdePipelineStageLauncher *self,
   IdePipelineStageLauncherPrivate *priv = ide_pipeline_stage_launcher_get_instance_private (self);
 
   g_return_if_fail (IDE_IS_PIPELINE_STAGE_LAUNCHER (self));
-  g_return_if_fail (IDE_IS_SUBPROCESS_LAUNCHER (clean_launcher));
+  g_return_if_fail (!clean_launcher || IDE_IS_SUBPROCESS_LAUNCHER (clean_launcher));
 
   if (g_set_object (&priv->clean_launcher, clean_launcher))
     g_object_notify_by_pspec (G_OBJECT (self), properties [PROP_CLEAN_LAUNCHER]);