still cannot format error union

src/main.zig

@@ -28,16 +28,16 @@ const filter_lib = @import("./filter.zig");
 
 var settings: config.Settings = undefined;
 
-pub fn main() u8 {
+pub fn main() !void {
     hello();
     initialize(alloc) catch unreachable;
     thread.register_main_tid(thread.self()) catch unreachable;
 
-    if (config.readfile(config.config_file_path())) |_| {
-        // settings = config_data;
-        // const dummy_payload = alloc.create(thread.CommandVerb) catch unreachable;
-        // _ = thread.create("gui", gui.go, dummy_payload, guiback) catch unreachable;
-        // _ = thread.create("heartbeat", heartbeat.go, dummy_payload, heartback) catch unreachable;
+    if (config.readfile(config.config_file_path())) |config_data| {
+        settings = config_data;
+        const dummy_payload = alloc.create(thread.CommandVerb) catch unreachable;
+        _ = try thread.create("gui", gui.go, dummy_payload, guiback);
+        //_ = thread.create("heartbeat", heartbeat.go, dummy_payload, heartback) catch unreachable;
 
         // while (true) {
         //     statewalk(alloc);
@@ -47,7 +47,6 @@ pub fn main() u8 {
     } else |_| {
         //log.err("config error: {!}\n", .{err});
     }
-    return 0;
 }
 
 fn initialize(allocator: std.mem.Allocator) !void {

src/thread.zig

@@ -66,7 +66,7 @@ pub fn signal(actor: *Actor, command: *Command) void {
     //const command_address_bytes: *const [8]u8 = @ptrCast([*]const u8, command)[0..8]; // not OK
     const command_address_bytes: *align(8) const [8]u8 = std.mem.asBytes(&command); // OK
     //const command_address_bytes = std.mem.asBytes(&@as(usize, @ptrToInt(command))); // OK
-    warn("tid {} is signaling command {*} id {} {*} to thread.wait() \n", .{ actor.thread_id, command, command.id, command.verb });
+    //warn("tid {} is signaling command {*} id {} {*} to thread.wait() \n", .{ actor.thread_id, command, command.id, command.verb });
     ipc.send(actor.client, command_address_bytes);
 }