Gracefully fail sending progress end

Summary: It can happen during shutdown that there's some race condition and the main thread's receiving end is dropped before this code runs. Not crashing here makes the exit cleaner and error message more readable

Reviewed By: robertoaloi

Differential Revision: D58285304

fbshipit-source-id: e7cd7225de2d448d649ea12b172daa88411ef66e

crates/elp/src/server/progress.rs

@@ -8,6 +8,7 @@
  */
 
 use crossbeam_channel::Receiver;
+use crossbeam_channel::SendError;
 use crossbeam_channel::Sender;
 use lsp_types::NumberOrString;
 use lsp_types::ProgressParams;
@@ -161,5 +162,7 @@ fn send_progress(sender: &Sender<ProgressTask>, token: NumberOrString, msg: Work
         token,
         value: ProgressParamsValue::WorkDone(msg),
     };
-    sender.send(ProgressTask::Notify(params)).unwrap();
+    if let Err(SendError(err)) = sender.send(ProgressTask::Notify(params)) {
+        log::error!("Failed to send progress message: {:?}", err);
+    }
 }