I'm trying to build and sign an add-in on a build server, which means everything has to run without a GUI. Unfortunately, I can't seem to get the ESRISignAddIn.exe tool to run without popping up a window. Even when I use the /r, /c, and /p options and the signing is successful, it still feels the need to pop up a message box to let me know everything is okay, which then causes it to throw an InvalidOperationException. (The message is "Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation. Specify the ServiceNotification or DefaultDesktopOnly style to display a notification from a service application.")
Is there a workaround for this? Perhaps an undocumented argument? Some fancy Windows trick to beat this dialog into submission?