I think it works now!!!!

src/rendering/vulkan/framebuffer.zig

@@ -49,7 +49,6 @@ pub fn getOrAdd(device: *const Device, attachments: []*const Image, width: u32,
         .height = @intCast(u16, height),
     };
 
-    std.debug.print("# attachments: {}\n\n", .{attachments.len});
     for (attachments) |attachment, i| {
         assert(attachment.view != .null_handle);
         key.attachments[i] = attachment.view;

src/rendering/vulkan/image.zig

@@ -52,8 +52,10 @@ pub const Image = struct {
         self.handle = handle;
         self.image_type = info.image_type;
         self.format = info.format;
-        self.state = State{};
-        self.state.layout = info.initial_layout;
+        self.state = State{
+            .layout = info.initial_layout,
+            .stage = .{ .color_attachment_output_bit = true }, // possibly needed
+        };
         self.usage = info.usage;
         self.width = @intCast(u16, info.extent.width);
         self.height = @intCast(u16, info.extent.height);
@@ -343,7 +345,6 @@ pub const Image = struct {
             (try Command.Buffer.get(self.owner, device)).touchImage(img);
             assert(img.state.layout == self.layout);
 
-            std.debug.print("inserted barrier: {}\n", .{inserted_barrier});
             return inserted_barrier;
         }
     };

src/rendering/vulkan/queues.zig

@@ -15,7 +15,11 @@ const sync = @import("sync.zig");
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 const allocator = gpa.allocator();
 
-const present_stages: vk.PipelineStageFlags = .{ .all_commands_bit = true, .top_of_pipe_bit = true, .bottom_of_pipe_bit = true };
+const present_stages: vk.PipelineStageFlags = .{
+    .all_commands_bit = true,
+    .top_of_pipe_bit = true,
+    .bottom_of_pipe_bit = true,
+};
 const present_access: vk.AccessFlags = .{
     .memory_read_bit = true,
     .memory_write_bit = true,

src/rendering/vulkan/swapchain.zig

@@ -352,14 +352,18 @@ pub const Swapchain = struct {
         return @intToFloat(f32, self.width) / @intToFloat(f32, self.height);
     }
 
+    pub fn getSwapIndex(self: *const Self) usize {
+        return self.image_index;
+    }
+
     pub fn getBackBufferRO(self: *const Self) *const Image {
-        const img = &self.images[self.image_index];
+        const img = &self.images[self.getSwapIndex()];
         assert(img.handle != .null_handle);
         return img;
     }
 
     pub fn getBackBuffer(self: *Self) *Image {
-        var img = &self.images[self.image_index];
+        var img = &self.images[self.getSwapIndex()];
         assert(img.handle != .null_handle);
         return img;
     }