Comment 16 for bug 2037417

So the cause of this, I am fairly sure, is the new "libmount-mountfd" support in util-linux which seems to have the consequence that "mount -o remount $mountpoint" fails for an overlay that references paths no longer available in the current mount namespace.

You can see the discussion of a similar-but-not-the-same issue here https://github.com/util-linux/util-linux/issues/1992

I'm trying to come up with a reproducer but I have to head afk now. I'll file a bug upstream when I get that done.

Maybe we should build util-linux with --disable-libmount-mountfd-support for now (bit late in the release cycle to be uploading util-linux though...)