diff --git a/src/events/event.zig b/src/events/event.zig
index 097e64f2..be92ba30 100644
--- a/src/events/event.zig
+++ b/src/events/event.zig
@@ -251,12 +251,12 @@ pub const EventHandler = struct {
                 Event.toInterface(evt) catch unreachable,
             }, &res) catch |e| log.err("event handler error: {any}", .{e});
         } else {
-            data.cbk.trycall(.{event}, &res) catch |e| log.err("event handler error: {any}", .{e});
+            data.cbk.trycall(.{event}, &res) catch |e| log.err("event handler error (null event): {any}", .{e});
         }
 
         // in case of function error, we log the result and the trace.
         if (!res.success) {
-            log.info("event handler error: {s}", .{res.result orelse "unknown"});
+            log.info("event handler error try catch: {s}", .{res.result orelse "unknown"});
             log.debug("{s}", .{res.stack orelse "no stack trace"});
         }
     }
diff --git a/src/xhr/xhr.zig b/src/xhr/xhr.zig
index 6d6269e9..0549a3e2 100644
--- a/src/xhr/xhr.zig
+++ b/src/xhr/xhr.zig
@@ -382,7 +382,11 @@ pub const XMLHttpRequest = struct {
         self.reset(alloc);
 
         self.url = try alloc.dupe(u8, url);
-        self.uri = std.Uri.parse(self.url.?) catch return DOMError.Syntax;
+        self.uri = std.Uri.parse(self.url.?) catch |err| {
+            log.debug("parse url ({s}): {any}", .{ self.url.?, err });
+            return DOMError.Syntax;
+        };
+        log.debug("open url ({s})", .{self.url.?});
         self.sync = if (asyn) |b| !b else false;
 
         self.state = OPENED;