[MacPorts] #63710: "Unable to open port: can't read "universal_possible": no such variable" after upgrading to 2.7.1

[MacPorts]

#63710: "Unable to open port: can't read "universal_possible": no such variable"
after upgrading to 2.7.1
-----------------------+--------------------
  Reporter:  singalen  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  base      |    Version:  2.7.1
Resolution:            |   Keywords:
      Port:            |
-----------------------+--------------------

Comment (by ryandesign):

 Well it says the error is:

 {{{
 DEBUG: system -W /Users/vic/src/amusement/macports-vic: /usr/bin/git pull
 --rebase --autostash
 There is no tracking information for the current branch.
 Please specify which branch you want to rebase against.
 See git-pull(1) for details.

     git pull <remote> <branch>

 If you wish to set tracking information for this branch you can do so
 with:

     git branch --set-upstream-to=origin/<branch> main

 Command failed: /usr/bin/git pull --rebase --autostash
 Exit code: 1
 }}}
 I don't know git well enough to advise you on resolving that.

 If you want MacPorts to selfupdate without attempting to update your git
 clone of macports-ports, with which it seems to be having some problem,
 use:
 {{{
 sudo port selfupdate --no-sync
 }}}
 When you fix whatever the problem is with your ports tree, you can run:
 {{{
 sudo port sync
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/63710#comment:8>
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