While trying to work with AWS RDS Postgres, it was interesting to see pg_dumpall failing to dump databases at all!
Delving further, for obvious reasons a managed service like this hides some global-information, which pg_dump(all) needs ... and no, this post is NOT about circumventing that.
This branch, gives a 'near' workaround for those who are okay with being able to extract all databases + (almost*) all Global information (Users etc.) in a single command. The *only* Global that can't be dumped are the User-Passwords, which for some people is okay, considering that they still get a scriptable way of taking a dump of all databases at one go, along with all User information.
Note: For those keen to know, the script just resets all users to be password-less, but that's better than having to do 'CREATE USER ... ' commands for your users by hand!
Down the line, I'll try to push this to the core, but for now, this works!
UPDATE: This patch is now a part of Native Postgres!! Read more here.