On Tue, Feb 24, 2026 at 12:23:33PM +0100, Florian Weimer wrote:

* Christian Brauner:

quoted

diff --git a/include/uapi/linux/mount.h b/include/uapi/linux/mount.h
index 5d3f8c9e3a62..acbc22241c9c 100644
--- a/include/uapi/linux/mount.h
+++ b/include/uapi/linux/mount.h

@@ -61,7 +61,8 @@
 /*
  * open_tree() flags.
  */
-#define OPEN_TREE_CLONE		1		/* Clone the target tree and attach the clone */
+#define OPEN_TREE_CLONE		(1 << 0)	/* Clone the target tree and attach the clone */

This change causes pointless -Werror=undef errors in projects that have
settled on the old definition.

Reported here:

  Bug 33921 - Building with Linux-7.0-rc1 errors on OPEN_TREE_CLONE
  <https://sourceware.org/bugzilla/show_bug.cgi?id=33921>

Send a patch to change it back, please.
Otherwise it might take a few days until I get around to it.