[MacPorts] #63374: xfig: Cannot install xfig for the arch 'arm64' because its dependency libpng is only installed for the arch 'x86_64' and the configured universal_archs 'x86_64 i386' are not sufficient

[MacPorts]

#63374: xfig: Cannot install xfig for the arch 'arm64' because its dependency
libpng is only installed for the arch 'x86_64' and the configured
universal_archs 'x86_64 i386' are not sufficient
-----------------------+--------------------------
  Reporter:  jgbroida  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.7.1
Resolution:            |   Keywords:  arm64 bigsur
      Port:  xfig      |
-----------------------+--------------------------

Comment (by jgbroida):

 You are correct that I used Time Machine to set up this new Mac. After
 your reply, I think I uninstalled MacPorts correctly (following Section
 2.4 I hope) and then ran the MacPorts installer again. I have Xcode and
 the Command Line Tools installed, but I get the same error message as
 before when I try to install xfig. I don't know enough Unix to understand
 how to update the macports.conf file as described in the migration
 procedure. A little step-by-step would be really helpful.

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Ticket URL: <https://trac.macports.org/ticket/63374#comment:2>
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