restore_ports.tcl script on fails on El Capitan with the error "infinite loop"

[JonoMH]

So, I've upgraded to El Capitan on my Mac and I've attempted to follow the instructions for migration to the new operating system here:

​https://trac.macports.org/wiki/Migration

However, after the restore_ports.tcl script immediately fails after that with the error message:

Error: we appear to be stuck, exiting...
infinite loop
    while executing
"sort_ports $portList"
    invoked from within
"set operationList [sort_ports $portList]"
    (file "./restore_ports.tcl" line 285)

I am confused as this does not seem to be due to conflicting ports in the list of previously installed ports that has been reported before and the error is different. My list of previously installed ports before upgrading to the new OS is long, so I've attached it as a file to this ticket. Thank you.

[JonoMH]

List of previously installed ports