[MacPorts] #60062: port 2.5.4: Error: Unable to open port: invalid command name "compiler.cxx_standard"

[MacPorts]

#60062: port 2.5.4: Error: Unable to open port: invalid command name
"compiler.cxx_standard"
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 Reporter:  nikgervae  |      Owner:  (none)
     Type:  defect     |     Status:  new
 Priority:  Normal     |  Milestone:
Component:  ports      |    Version:  2.5.4
 Keywords:             |       Port:
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 I am on MacOS High Sierra 10.13.6, trying to update my ports. I ran "sudo
 port selfupdate" and then, I ran "sudo port upgrade outdated" and got this
 output:
 --
 Error: Unable to open port: invalid command name "compiler.cxx_standard"
 Error: Follow https://guide.macports.org/#project.tickets to report a bug.
 --

 If I try "sudo port upgrade installed", I instead get this error:
 --
 Error: Unable to open port: can't set "compiler.blacklist": invalid
 command name "compiler.command_line_tools_version"
 Error: Follow https://guide.macports.org/#project.tickets to report a bug.
 --

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Ticket URL: <https://trac.macports.org/ticket/60062>
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