This patch is based on manually applying fixes from 
https://github.com/dbus2/zbus/commit/fd5a4fa5f446320a4eee952288b338382a5d14ab
to the zbus 1.x codebase.

Be aware that this patch only works with a correspondingly patched version
of zvariant 2.x. Using it with the zvariant crate from crates.io will not
work.

Index: rust-zbus-1-1.9.3/Cargo.toml
===================================================================
--- rust-zbus-1-1.9.3.orig/Cargo.toml
+++ rust-zbus-1-1.9.3/Cargo.toml
@@ -40,7 +40,7 @@ version = "1.3.1"
 version = "2.1"
 
 [dependencies.enumflags2]
-version = "0.6.4"
+version = "0.7.7"
 features = ["serde"]
 
 [dependencies.fastrand]
Index: rust-zbus-1-1.9.3/src/fdo.rs
===================================================================
--- rust-zbus-1-1.9.3.orig/src/fdo.rs
+++ rust-zbus-1-1.9.3/src/fdo.rs
@@ -3,7 +3,7 @@
 //! The D-Bus specification defines the message bus messages and some standard interfaces that may
 //! be useful across various D-Bus applications. This module provides their proxy.
 
-use enumflags2::BitFlags;
+use enumflags2::{bitflags,BitFlags};
 use serde::{Deserialize, Serialize};
 use serde_repr::{Deserialize_repr, Serialize_repr};
 use std::collections::HashMap;
@@ -114,8 +114,9 @@ trait Stats {
 /// The flags used by the bus [`request_name`] method.
 ///
 /// [`request_name`]: struct.DBusProxy.html#method.request_name
+#[bitflags]
 #[repr(u32)]
-#[derive(Type, BitFlags, Debug, PartialEq, Copy, Clone, Serialize, Deserialize)]
+#[derive(Type, Debug, PartialEq, Copy, Clone, Serialize, Deserialize)]
 pub enum RequestNameFlags {
     /// If an application A specifies this flag and succeeds in becoming the owner of the name, and
     /// another application B later calls [`request_name`] with the [`ReplaceExisting`] flag, then
Index: rust-zbus-1-1.9.3/src/lib.rs
===================================================================
--- rust-zbus-1-1.9.3.orig/src/lib.rs
+++ rust-zbus-1-1.9.3/src/lib.rs
@@ -207,7 +207,7 @@ mod tests {
         os::unix::io::{AsRawFd, FromRawFd},
     };
 
-    use enumflags2::BitFlags;
+    use enumflags2::{bitflags,BitFlags};
     use serde_repr::{Deserialize_repr, Serialize_repr};
 
     use zvariant::{derive::Type, Fd, OwnedValue, Type};
@@ -313,4 +313,5 @@ mod tests {
     // Let's try getting us a fancy name on the bus
+    #[bitflags]
     #[repr(u32)]
-    #[derive(Type, BitFlags, Debug, PartialEq, Copy, Clone)]
+    #[derive(Type, Debug, PartialEq, Copy, Clone)]
     enum RequestNameFlags {
Index: rust-zbus-1-1.9.3/src/message_header.rs
===================================================================
--- rust-zbus-1-1.9.3.orig/src/message_header.rs
+++ rust-zbus-1-1.9.3/src/message_header.rs
@@ -1,6 +1,6 @@
 use std::convert::TryFrom;
 
-use enumflags2::BitFlags;
+use enumflags2::{bitflags,BitFlags};
 use serde::{Deserialize, Serialize};
 use serde_repr::{Deserialize_repr, Serialize_repr};
 
@@ -72,8 +72,9 @@ impl From<u8> for MessageType {
 }
 
 /// Pre-defined flags that can be passed in Message header.
+#[bitflags]
 #[repr(u8)]
-#[derive(Debug, Copy, Clone, PartialEq, BitFlags, Type)]
+#[derive(Debug, Copy, Clone, PartialEq, Type)]
 pub enum MessageFlags {
     /// This message does not expect method return replies or error replies, even if it is of a type
     /// that can have a reply; the reply should be omitted.