When publishing to an IPS depotd server you may see the line

pkgsend: Publisher 'default' has no repositories that support the 'open/0' operation.

If the depotd server will show you a web page but publishing does not work with pkgsend you may have the server setup in read only mode. svccfg will allow you to change the property with

svccfg -s pkg/server setprop pkg/readonly = false

Don't do this to a server on the internet though, placing an HTTP server in front of depotd will allow you to add authentication. This is otherwise insecure!