Change CommandPanic payload type to Option<String>

Previously, it was Box<dyn Any + Send> - making the entire type not Sync. This wasn't intentional.

This is technically a breaking change, but since CommandPanic was only introduced a few days ago, and was itself a breaking change, this is basically just a quick hotfix reversal of a breaking change.

src/lib.rs

@@ -472,10 +472,29 @@ pub type BoxFuture<'a, T> = std::pin::Pin<Box<dyn std::future::Future<Output = T
 /// Internal wrapper function for catch_unwind that respects the `handle_panics` feature flag
 async fn catch_unwind_maybe<T>(
     fut: impl std::future::Future<Output = T>,
-) -> Result<T, Box<dyn std::any::Any + Send + 'static>> {
+) -> Result<T, Option<String>> {
     #[cfg(feature = "handle_panics")]
-    let res = futures_util::FutureExt::catch_unwind(std::panic::AssertUnwindSafe(fut)).await;
+    let res = futures_util::FutureExt::catch_unwind(std::panic::AssertUnwindSafe(fut))
+        .await
+        .map_err(|e| {
+            if let Some(s) = e.downcast_ref::<&str>() {
+                Some(s.to_string())
+            } else if let Ok(s) = e.downcast::<String>() {
+                Some(*s)
+            } else {
+                None
+            }
+        });
     #[cfg(not(feature = "handle_panics"))]
     let res = Ok(fut.await);
     res
 }
+
+#[cfg(test)]
+mod tests {
+    fn assert_send_sync<T: Send + Sync>() {}
+
+    fn _test_framework_error_send_sync<'a, U: Send + Sync + 'static, E: Send + Sync + 'static>() {
+        assert_send_sync::<crate::FrameworkError<'a, U, E>>();
+    }
+}

src/structs/framework_error.rs

@@ -49,7 +49,13 @@ pub enum FrameworkError<'a, U, E> {
     /// normal errors!
     CommandPanic {
         /// Panic payload which was thrown in the command code
-        payload: Box<dyn std::any::Any + Send + 'static>,
+        ///
+        /// If a panic was thrown via [`std::panic::panic_any()`] and the payload was neither &str,
+        /// nor String, the payload is `None`.
+        ///
+        /// The reason the original [`Box<dyn Any + Send>`] payload isn't provided here is that it
+        /// would make [`FrameworkError`] not [`Sync`] anymore.
+        payload: Option<String>,
         /// Command context
         ctx: crate::Context<'a, U, E>,
     },