diff --git a/crates/gpui2/src/app.rs b/crates/gpui2/src/app.rs
index b20470fb18..3bc0c14f9a 100644
--- a/crates/gpui2/src/app.rs
+++ b/crates/gpui2/src/app.rs
@@ -47,10 +47,10 @@ impl AppCell {
         AppRef(self.app.borrow())
     }
 
-    pub fn borrow_mut(&self, label: &str) -> AppRefMut {
+    pub fn borrow_mut(&self) -> AppRefMut {
         let thread_id = std::thread::current().id();
 
-        eprintln!(">>> borrowing {thread_id:?}: {label}");
+        eprintln!(">>> borrowing {thread_id:?}");
         AppRefMut(self.app.borrow_mut())
     }
 }
@@ -85,7 +85,7 @@ impl App {
         let platform = self.0.borrow().platform.clone();
         platform.run(Box::new(move || {
             dbg!("run callback");
-            let cx = &mut *this.borrow_mut("app::borrow_mut");
+            let cx = &mut *this.borrow_mut();
             on_finish_launching(cx);
         }));
     }
@@ -99,7 +99,7 @@ impl App {
         let this = Rc::downgrade(&self.0);
         self.0.borrow().platform.on_open_urls(Box::new(move |urls| {
             if let Some(app) = this.upgrade() {
-                callback(urls, &mut *app.borrow_mut("app.rs::on_open_urls"));
+                callback(urls, &mut *app.borrow_mut());
             }
         }));
         self
@@ -110,11 +110,14 @@ impl App {
         F: 'static + FnMut(&mut AppContext),
     {
         let this = Rc::downgrade(&self.0);
-        self.0.borrow_mut("app.rs::on_reopen").platform.on_reopen(Box::new(move || {
-            if let Some(app) = this.upgrade() {
-                callback(&mut app.borrow_mut("app.rs::on_reopen(callback)"));
-            }
-        }));
+        self.0
+            .borrow_mut()
+            .platform
+            .on_reopen(Box::new(move || {
+                if let Some(app) = this.upgrade() {
+                    callback(&mut app.borrow_mut());
+                }
+            }));
         self
     }
 
diff --git a/crates/gpui2/src/app/async_context.rs b/crates/gpui2/src/app/async_context.rs
index 4fffdc693f..f45457936c 100644
--- a/crates/gpui2/src/app/async_context.rs
+++ b/crates/gpui2/src/app/async_context.rs
@@ -29,7 +29,7 @@ impl Context for AsyncAppContext {
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
         dbg!("BUILD MODEL A");
-        let mut app = app.borrow_mut("gpui2/async_context.rs::build_model");
+        let mut app = app.borrow_mut();
         Ok(app.build_model(build_model))
     }
 
@@ -43,7 +43,7 @@ impl Context for AsyncAppContext {
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
         dbg!("UPDATE MODEL B");
-        let mut app = app.borrow_mut("gpui2/async_context.rs::update_model");
+        let mut app = app.borrow_mut();
         Ok(app.update_model(handle, update))
     }
 
@@ -53,7 +53,7 @@ impl Context for AsyncAppContext {
     {
         let app = self.app.upgrade().context("app was released")?;
         dbg!("UPDATE WINDOW C");
-        let mut lock = app.borrow_mut("gpui2/async_context::update_window");
+        let mut lock = app.borrow_mut();
         lock.update_window(window, f)
     }
 }
@@ -65,7 +65,7 @@ impl AsyncAppContext {
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
         dbg!("REFRESH");
-        let mut lock = app.borrow_mut("async_context.rs::refresh");
+        let mut lock = app.borrow_mut();
         lock.refresh();
         Ok(())
     }
@@ -83,7 +83,7 @@ impl AsyncAppContext {
             .app
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
-        let mut lock = app.borrow_mut("async_context.rs::update");
+        let mut lock = app.borrow_mut();
         Ok(f(&mut *lock))
     }
 
@@ -99,7 +99,7 @@ impl AsyncAppContext {
             .app
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
-        let mut lock = app.borrow_mut("open_window");
+        let mut lock = app.borrow_mut();
         Ok(lock.open_window(options, build_root_view))
     }
 
@@ -116,7 +116,7 @@ impl AsyncAppContext {
             .app
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
-        let app = app.borrow_mut("has_global");
+        let app = app.borrow_mut();
         Ok(app.has_global::<G>())
     }
 
@@ -126,7 +126,7 @@ impl AsyncAppContext {
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
         dbg!("read global");
-        let app = app.borrow_mut("async_context.rs::read_global");
+        let app = app.borrow_mut();
         Ok(read(app.global(), &app))
     }
 
@@ -136,7 +136,7 @@ impl AsyncAppContext {
     ) -> Option<R> {
         let app = self.app.upgrade()?;
         dbg!("try read global");
-        let app = app.borrow_mut("async_context.rs::try_read_global");
+        let app = app.borrow_mut();
         Some(read(app.try_global()?, &app))
     }
 
@@ -149,7 +149,7 @@ impl AsyncAppContext {
             .upgrade()
             .ok_or_else(|| anyhow!("app was released"))?;
         dbg!("update global");
-        let mut app = app.borrow_mut("async_context.rs::update_global");
+        let mut app = app.borrow_mut();
         Ok(app.update_global(update))
     }
 }
diff --git a/crates/gpui2/src/app/test_context.rs b/crates/gpui2/src/app/test_context.rs
index f0ee988ebb..7ef53d3e12 100644
--- a/crates/gpui2/src/app/test_context.rs
+++ b/crates/gpui2/src/app/test_context.rs
@@ -24,7 +24,7 @@ impl Context for TestAppContext {
     where
         T: 'static,
     {
-        let mut app = self.app.borrow_mut("test_context.rs::build_model");
+        let mut app = self.app.borrow_mut();
         app.build_model(build_model)
     }
 
@@ -33,7 +33,7 @@ impl Context for TestAppContext {
         handle: &Model<T>,
         update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
     ) -> Self::Result<R> {
-        let mut app = self.app.borrow_mut("test_context::update_model");
+        let mut app = self.app.borrow_mut();
         app.update_model(handle, update)
     }
 
@@ -41,7 +41,7 @@ impl Context for TestAppContext {
     where
         F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
     {
-        let mut lock = self.app.borrow_mut("test_context::update_window");
+        let mut lock = self.app.borrow_mut();
         lock.update_window(window, f)
     }
 }
@@ -65,11 +65,11 @@ impl TestAppContext {
     }
 
     pub fn quit(&self) {
-        self.app.borrow_mut("test_context.rs::quit").quit();
+        self.app.borrow_mut().quit();
     }
 
     pub fn refresh(&mut self) -> Result<()> {
-        let mut app = self.app.borrow_mut("test_context.rs::refresh");
+        let mut app = self.app.borrow_mut();
         app.refresh();
         Ok(())
     }
@@ -83,7 +83,7 @@ impl TestAppContext {
     }
 
     pub fn update<R>(&self, f: impl FnOnce(&mut AppContext) -> R) -> R {
-        let mut cx = self.app.borrow_mut("test_context::update");
+        let mut cx = self.app.borrow_mut();
         cx.update(f)
     }
 
@@ -117,7 +117,7 @@ impl TestAppContext {
         &mut self,
         update: impl FnOnce(&mut G, &mut AppContext) -> R,
     ) -> R {
-        let mut lock = self.app.borrow_mut("test_context.rs::update_global");
+        let mut lock = self.app.borrow_mut();
         lock.update_global(update)
     }
 
diff --git a/crates/gpui2/src/platform.rs b/crates/gpui2/src/platform.rs
index cdce67d8c1..a4be21ddf3 100644
--- a/crates/gpui2/src/platform.rs
+++ b/crates/gpui2/src/platform.rs
@@ -69,7 +69,7 @@ pub(crate) trait Platform: 'static {
     fn set_display_link_output_callback(
         &self,
         display_id: DisplayId,
-        callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp)>,
+        callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp) + Send>,
     );
     fn start_display_link(&self, display_id: DisplayId);
     fn stop_display_link(&self, display_id: DisplayId);
diff --git a/crates/gpui2/src/platform/mac/display_linker.rs b/crates/gpui2/src/platform/mac/display_linker.rs
index 6d8235a381..b63cf24e26 100644
--- a/crates/gpui2/src/platform/mac/display_linker.rs
+++ b/crates/gpui2/src/platform/mac/display_linker.rs
@@ -26,13 +26,13 @@ impl MacDisplayLinker {
     }
 }
 
-type OutputCallback = Mutex<Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp)>>;
+type OutputCallback = Mutex<Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp) + Send>>;
 
 impl MacDisplayLinker {
     pub fn set_output_callback(
         &mut self,
         display_id: DisplayId,
-        output_callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp)>,
+        output_callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp) + Send>,
     ) {
         if let Some(mut system_link) = unsafe { sys::DisplayLink::on_display(display_id.0) } {
             let callback = Arc::new(Mutex::new(output_callback));
diff --git a/crates/gpui2/src/platform/mac/platform.rs b/crates/gpui2/src/platform/mac/platform.rs
index fdc7fd6ae5..7065c02e87 100644
--- a/crates/gpui2/src/platform/mac/platform.rs
+++ b/crates/gpui2/src/platform/mac/platform.rs
@@ -494,7 +494,7 @@ impl Platform for MacPlatform {
     fn set_display_link_output_callback(
         &self,
         display_id: DisplayId,
-        callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp)>,
+        callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp) + Send>,
     ) {
         self.0
             .lock()
diff --git a/crates/gpui2/src/platform/test/platform.rs b/crates/gpui2/src/platform/test/platform.rs
index 524611b620..b4f3c739e6 100644
--- a/crates/gpui2/src/platform/test/platform.rs
+++ b/crates/gpui2/src/platform/test/platform.rs
@@ -81,7 +81,7 @@ impl Platform for TestPlatform {
     fn set_display_link_output_callback(
         &self,
         _display_id: DisplayId,
-        _callback: Box<dyn FnMut(&crate::VideoTimestamp, &crate::VideoTimestamp)>,
+        _callback: Box<dyn FnMut(&crate::VideoTimestamp, &crate::VideoTimestamp) + Send>,
     ) {
         unimplemented!()
     }
diff --git a/crates/ui2/src/elements/avatar.rs b/crates/ui2/src/elements/avatar.rs
index ca773397ca..357e573f7c 100644
--- a/crates/ui2/src/elements/avatar.rs
+++ b/crates/ui2/src/elements/avatar.rs
@@ -62,6 +62,9 @@ mod stories {
                     "https://avatars.githubusercontent.com/u/326587?v=4",
                 ))
                 // .child(Avatar::new(
+                //     "https://avatars.githubusercontent.com/u/326587?v=4",
+                // ))
+                // .child(Avatar::new(
                 //     "https://avatars.githubusercontent.com/u/482957?v=4",
                 // ))
                 // .child(Avatar::new(