El Capitan migration

[Joseph C Slater, PhD, PE]

Is El Capitan migration "working" properly? I updated to the GM recently and the macport installations I use seem to work fine, however port selfupdate gave 

"Error: Current platform "darwin 15" does not match expected platform "darwin 14"
Error: If you upgraded your OS, please follow the migration instructions: https://trac.macports.org/wiki/Migration
OS platform mismatch
    while executing
"mportinit ui_options global_options global_variations"
Error: /opt/local/bin/port: Failed to initialize MacPorts, OS platform mismatch"

Which I can understand fine. What I'm concerned about is that things are working now (of course, i want to keep upgrading my packages) but will they continue to work if I follow the procedures to migrate (https://trac.macports.org/wiki/Migration). What I don't see is an installation package for El Capitan. Will building from source (as posted) work now or is there a beta that must be used... etc.?

This must have been rehashed elsewhere, but I didn't see explicit instructions browsing older emails.
Thank You,
Joe