Merge pull request cli#13353 from adehad/fix/telemetry-windows-console-flash

fix(telemetry): prevent tzutil console flash on Windows

Author: williammartin

internal/telemetry/detach_windows.go

@@ -10,7 +10,15 @@ import (
 
 // detachAttrs returns SysProcAttr configured to place the child in its own
 // process group so that console signals (Ctrl+C) delivered to the parent's
-// group are not forwarded to the child.
+// group are not forwarded to the child, and to suppress any console window
+// for the child and its descendants.
+//
+// CREATE_NO_WINDOW is preferred over DETACHED_PROCESS here: DETACHED_PROCESS
+// removes the console entirely, which causes any console-subsystem descendant
+// (e.g. tzutil.exe invoked transitively to resolve the local IANA timezone)
+// to allocate a fresh conhost window, producing a visible flash on every gh
+// invocation. CREATE_NO_WINDOW gives the child a non-visible console that
+// descendants can inherit, avoiding the flash.
 func detachAttrs() *syscall.SysProcAttr {
-	return &syscall.SysProcAttr{CreationFlags: windows.CREATE_NEW_PROCESS_GROUP | windows.DETACHED_PROCESS}
+	return &syscall.SysProcAttr{CreationFlags: windows.CREATE_NEW_PROCESS_GROUP | windows.CREATE_NO_WINDOW}
 }