restore_ports.tcl script fails with "can't read "replaced_by": no such variable"

[jbrinchmann@…]

I'm on Yosemite (10.10.3) and was trying to upgrade my MacPorts installation. I followed the instructions at ​https://trac.macports.org/wiki/Migration. For the sudo port clean all command I ran into an error:

"---> Cleaning capstone Error: Unable to open port: can't read "replaced_by": no such variable"

I then ran the clean explicitly on all installed packages and that completed without problems.

When trying to run restore_ports.tcl, however, the result was a failure:

sudo ./restore_ports.tcl myports.txt

can't read "replaced_by": no such variable

while executing

"default long_description "This port has been replaced by ${replaced_by}.""

(file "/opt/local/var/macports/sources/rsync.macports.org/release/tarballs/ports/_resources/port1.0/group/obsolete-1.0.tcl" line 52) invoked from within

"source /opt/local/var/macports/sources/rsync.macports.org/release/tarballs/ports/_resources/port1.0/group/obsolete-1.0.tcl"

("uplevel" body line 1) invoked from within

"uplevel "source $groupFile""

(procedure "PortGroup" line 20) invoked from within

"PortGroup obsolete 1.0"

(file "Portfile" line 4) invoked from within

"source Portfile"

invoked from within

"$workername eval source Portfile"

(procedure "mportopen" line 41) invoked from within

"mportopen $portInfo(porturl) [list subport $portInfo(name)] $variantInfo" Unable to open port 'CarbonHeaders': can't read "replaced_by": no such variable

while executing

"dependenciesForPort $name $variants"

(procedure "sort_ports" line 46) invoked from within

"sort_ports $portList"

invoked from within

"set operationList [sort_ports $portList]"

(file "./restore_ports.tcl" line 285)

This was a bit too obscure an error for me.