project: Print error causes when failing to spawn lsp command (#36163)

cc https://github.com/zed-industries/zed/issues/34666

Display printing anyhow errors only renders the error itself, but not
any of its causes so we've been dropping the important context when
showing the issue to the users.

Release Notes:

- N/A

crates/lsp/src/lsp.rs

@@ -318,6 +318,8 @@ impl LanguageServer {
         } else {
             root_path.parent().unwrap_or_else(|| Path::new("/"))
         };
+        let root_uri = Url::from_file_path(&working_dir)
+            .map_err(|()| anyhow!("{working_dir:?} is not a valid URI"))?;
 
         log::info!(
             "starting language server process. binary path: {:?}, working directory: {:?}, args: {:?}",
@@ -345,8 +347,6 @@ impl LanguageServer {
         let stdin = server.stdin.take().unwrap();
         let stdout = server.stdout.take().unwrap();
         let stderr = server.stderr.take().unwrap();
-        let root_uri = Url::from_file_path(&working_dir)
-            .map_err(|()| anyhow!("{working_dir:?} is not a valid URI"))?;
         let server = Self::new_internal(
             server_id,
             server_name,

crates/project/src/lsp_store.rs

@@ -390,13 +390,17 @@ impl LocalLspStore {
                         delegate.update_status(
                             adapter.name(),
                             BinaryStatus::Failed {
-                                error: format!("{err}\n-- stderr--\n{log}"),
+                                error: if log.is_empty() {
+                                    format!("{err:#}")
+                                } else {
+                                    format!("{err:#}\n-- stderr --\n{log}")
+                                },
                             },
                         );
-                        let message =
-                            format!("Failed to start language server {server_name:?}: {err:#?}");
-                        log::error!("{message}");
-                        log::error!("server stderr: {log}");
+                        log::error!("Failed to start language server {server_name:?}: {err:?}");
+                        if !log.is_empty() {
+                            log::error!("server stderr: {log}");
+                        }
                         None
                     }
                 }