KAN-208: Fix Shift+Y branch copy crash on Linux/Wayland

.changeset/kan-208-fix-shift-y-branch-copy-crash-on-linux-nixos-wayland.md

@@ -0,0 +1,9 @@
+---
+bump: patch
+---
+
+- docs: document Linux clipboard manager requirement
+- refactor(tui): replace last_error with unified Banner system
+- feat(tui): add reusable Banner component
+- feat(tui): enable Wayland support with clipboard manager handoff
+- chore: add Wayland/X11 clipboard dependencies

README.md

@@ -54,6 +54,15 @@ cargo install --path crates/kanban-cli
 nix run github:fulsomenko/kanban
 ```
 
+### Linux Clipboard Support
+
+For clipboard operations (`y`/`Y` to copy branch names) to persist after exiting, you need a clipboard manager running:
+
+- **Wayland**: `wl-clip-persist`, `cliphist`, `clipman`, or your DE's built-in manager
+- **X11**: Most desktop environments include one by default
+
+Without a clipboard manager, copied content is lost when the app exits (this is a Linux platform limitation, not a bug).
+
 ## Quick Start
 
 ### TUI

crates/kanban-tui/Cargo.toml

@@ -25,7 +25,7 @@ uuid.workspace = true
 chrono.workspace = true
 async-trait.workspace = true
 tracing.workspace = true
-arboard = "3.4"
+arboard = { version = "3.4", features = ["wayland-data-control"] }
 pulldown-cmark = "0.13"
 
 [dev-dependencies]

crates/kanban-tui/src/app.rs

@@ -2,7 +2,7 @@ use crate::{
     card_list::{CardList, CardListId},
     card_list_component::{CardListComponent, CardListComponentConfig},
     clipboard,
-    components::generic_list::ListComponent,
+    components::{generic_list::ListComponent, Banner},
     editor::edit_in_external_editor,
     events::{Event, EventHandler},
     filters::FilterDialogState,
@@ -93,7 +93,7 @@ pub struct App {
     pub file_watcher: Option<kanban_persistence::FileWatcher>,
     pub save_worker_handle: Option<tokio::task::JoinHandle<()>>,
     pub save_completion_rx: Option<tokio::sync::mpsc::UnboundedReceiver<()>>,
-    pub last_error: Option<(String, Instant)>,
+    pub banner: Option<Banner>,
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -265,7 +265,7 @@ impl App {
             file_watcher: None,
             save_worker_handle: None,
             save_completion_rx,
-            last_error: None,
+            banner: None,
         };
 
         if let Some(ref filename) = save_file {
@@ -316,16 +316,16 @@ impl App {
         self.push_mode(AppMode::Dialog(dialog));
     }
 
-    pub fn set_error(&mut self, message: String) {
-        self.last_error = Some((message, Instant::now()));
+    pub fn set_error(&mut self, message: impl Into<String>) {
+        self.banner = Some(Banner::error(message));
     }
 
-    pub fn clear_error(&mut self) {
-        self.last_error = None;
+    pub fn set_success(&mut self, message: impl Into<String>) {
+        self.banner = Some(Banner::success(message));
     }
 
-    pub fn should_clear_error(&self) -> bool {
-        false
+    pub fn clear_banner(&mut self) {
+        self.banner = None;
     }
 
     fn keycode_matches_binding_key(
@@ -459,9 +459,9 @@ impl App {
         use crossterm::event::KeyCode;
         let mut should_restart_events = false;
 
-        // Clear error on any key press
-        if self.last_error.is_some() {
-            self.clear_error();
+        // Clear banner on any key press
+        if self.banner.is_some() {
+            self.clear_banner();
             return false;
         }
 
@@ -1594,9 +1594,11 @@ impl App {
                             Event::Tick => {
                                 self.handle_animation_tick();
 
-                                // Auto-clear errors after 5 seconds
-                                if self.should_clear_error() {
-                                    self.clear_error();
+                                // Auto-clear banner after 3 seconds
+                                if let Some(ref banner) = self.banner {
+                                    if banner.is_expired(std::time::Duration::from_secs(3)) {
+                                        self.clear_banner();
+                                    }
                                 }
 
                                 // Handle pending conflict resolution actions
@@ -1879,9 +1881,9 @@ impl App {
                             self.app_config.effective_default_card_prefix(),
                         );
                         if let Err(e) = clipboard::copy_to_clipboard(&output) {
-                            tracing::error!("Failed to copy to clipboard: {}", e);
+                            self.set_error(format!("Failed to copy: {}", e));
                         } else {
-                            tracing::info!("Copied {}: {}", output_type, output);
+                            self.set_success(format!("Copied {}", output_type));
                         }
                     }
                 }

crates/kanban-tui/src/clipboard.rs

@@ -1,7 +1,24 @@
 use std::io;
 
 pub fn copy_to_clipboard(text: &str) -> io::Result<()> {
-    arboard::Clipboard::new()
-        .and_then(|mut clipboard| clipboard.set_text(text))
-        .map_err(io::Error::other)
+    let mut clipboard = arboard::Clipboard::new().map_err(io::Error::other)?;
+
+    #[cfg(target_os = "linux")]
+    {
+        use arboard::SetExtLinux;
+        use std::time::{Duration, Instant};
+
+        // wait_until gives clipboard managers time to take ownership
+        // This prevents clipboard clearing when our app exits
+        clipboard
+            .set()
+            .wait_until(Instant::now() + Duration::from_millis(250))
+            .text(text.to_owned())
+            .map_err(io::Error::other)
+    }
+
+    #[cfg(not(target_os = "linux"))]
+    {
+        clipboard.set_text(text).map_err(io::Error::other)
+    }
 }