I discovered that Add-RabbitMQPermission does not work, because it attempts to pass a -ComputerName to Get-RabbitMQPermission. These were renamed to BaseUri in 27b7c8b3321f7ca2f7e5ac9476b2ed605492aa8e (with alias HostName) but these were missed.
I'm about to create a pull request to address this.
I discovered that Add-RabbitMQPermission does not work, because it attempts to pass a -ComputerName to Get-RabbitMQPermission. These were renamed to BaseUri in 27b7c8b3321f7ca2f7e5ac9476b2ed605492aa8e (with alias HostName) but these were missed.
I'm about to create a pull request to address this.