When libdevmapper is built without UDEV_SYNC_SUPPORT (e.g. on Alpine/postmarketOS), it creates a device node under /dev/mapper/ instead of relying on udev to create a symlink.
When libdevmapper is built without UDEV_SYNC_SUPPORT (e.g. on Alpine/postmarketOS), it creates a device node under /dev/mapper/ instead of relying on udev to create a symlink.